Subterrain

I really had a blast with this game especially considering that you can pick it up very cheap on sale.
After a quick tutorial level you learn that you need do several things pretty much all at once.
1) Don't die, Eat, Sleep, Drink, Piss, ♥♥♥♥, and Keep your infection rates down. Keep the global infection rates down, keep the individual sector infection rates down. Don't run out of power (ammo and flashlight), oxygen or let yourself freeze to death.
2) Manage the reactor cores, if the reactor goes down, its over and yes there will be invasions.
3) Find upgrades for your base, which includes 4 sectors and the reactor cores and more.
4) Loot everything with your tiny backpack so you can keep upgrading your equipment, which includes armor, guns, grenades, drugs, and medicine... and more.
5) Manage your time effectively so you don't fall behind on anything from numbers 1 through 4.
The main thing you'll need are the data chips for the 4 sectors, problem is you don't know where they are... and neither does the game (for most of them) because its randomized...
If this sounds like a lot, its because it is, and the game does not do a very good job teaching you any strategy for how to handle all of this or even really where to start other than to just find those data chips... somewhere out there, but once you start to understand the flow of the game its gameplay loop is really fun, go out, survive, kill, loot, comeback research, repair, sleep... and slowly over time you'll go from barely hanging on to winning back the planet.
Making tangible progress felt amazing, and kept me coming back, I would get excited about finding a new upgrade chip or maxing out my SMG research or making all new cores for the reactor or finally being able to grow tomatoes.
I'm gonna give everyone a hint here... it's much better if you kind of spread the love around, but not too much. Stick close to home and do just 1-2 levels of an area, then retreat, repeat that only at the closest 4 locations until you have all your level 2 chips... by now you should know enough about the game to get your feet under you, and what you need to do to push ahead.
On the down side the game is so overwhelming at times that almost anything you've missed or screwed up can feel like a mistake or bad design or a bug... if you miss a critical keycard or quest item, that can be real trouble. It can be crippling if you've dropped it somewhere you shouldn't have (don't drop stuff anywhere but your base).
Subterrain can get pretty darn repetitive as you have a lot of areas to explore... like nearly 80 floors of rooms and doors and corridors. I will admit the game almost wore me out but I wanted to see the end, and I'm glad I did. There's multiple endings and I think overall the story was actually pretty good.
To sum it all up I had a fantastic time with Subterrain and I think it could really appeal to a lot of people who like survival shooters, or crafting, upgrading, planning and time management. Especially for the low price point... its an amazing value, if you manage to figure out those first few steps. For the most sadistic there's also higher difficulties and permadeath modes to play through.

Subterrain is an interesting game. It's a game that's been on my mind for a long time, it's a game I had meant to 100% for literally years until I got around to it this year, or last year. It's also something of a tenuous recommend from myself. I recommend the game for what I like about it, what I find interesting, and what it's trying to do. What holds this game back is some of its mechanics feeling surface level, the enemies being dull, and it's incredibly padded playtime. I think it's a really interesting and fun concept for a survival game, its specific type is the kind of thing that drilled into a soft spot in my skull. I would *love* to see a game like this, more in depth or expanded in some way.
The game goes like this: You wake up in prison, break out because the power failed, discover that everyone is dead and mutants are all over the mars complex, you head down to the central hub area that becomes your base of operations and you launch excursions out into other parts of the facility connected to the tram network in an attempt to figure out what's going on and get out alive. You'll be scavenging for materials, junk, and food as you progress through what are effectively dungeons with various levels, anywhere from 2-10, to find what you need. All the while you're racing against the clock, as enemy density and threat level marches ever onward, eventually to the point where you'll be facing regular invasions on the central hub where hordes of mutants attempt to destroy the reactor powering the facility.
Actual upgrades and "Progress" (player wise) comes from sticking items into researching machines, destroying them in the process but allowing fabrication machines to construct higher tiers. Past a certain point, items are considered a higher 'tier', and as such more advanced software for the machines must be found, researched, built, and slotted into the machines so you can access stronger items. There's also a botany and mining area that you'll always have running to produce minerals, fruits and veg for you to break down into useful crafting resources.
The big problem with this game is its padding. What I mean by this is that toward mid and late game, these "Dungeons" (other areas in the facility, like casinos, shopping districts, and so on) begin to get LONG. You end up having to explore entire levels so you don't miss something potentially important, as the Software Upgrades don't tend to be designated with specific floor numbers, just the district. As enemy density and threat goes up, this turns every floor into a real slog. Paired with your limited time on excursions (hunger, thirst, fatigue, the need to use the toilet, battery life, lifesupport), you end up shooting through the same enemies for extended periods of time. This isn't too bad on the normal and easy difficulties, most of the tedium comes at that point from going through very samey looking areas that don't have anything *interesting* in them to do or interact with other than blindly sprinting around while you're shot up on speed boosting drugs, on the higher difficulties, though, you very quickly end up in a spot where all of the higher health, more dangerous, enemies spawn. This means it takes longer, which means enemy density and threat goes up, feedback loop and all that. It all adds up to make a very boring, repetitive experience. Coupled with the fact you don't have enough power for a lot of the game to keep areas running to run the life support in those areas, IF you find them, to slow down enemy spawn rates for that area.
Spoilers from here onward:
In the end game, you find "Purifiers" that not only slow down enemy spawns drastically, but are able to COMPLETELY remove enemies and their spawns from areas, completely securing them. This is required to be able to fight the two final bosses, which are not great, and this doubles spawn rate once you acquire the blueprints. You are warned ahead of time, of course, and you should only do this once you have all the best gear. On the highest difficulty, this meant that every single area was *fully* red. This meant I spent real life hours slogging through every district, one by one, to slowly clean them out of all the highest tier, spongiest, boring and deadly enemies in the game. I open a door, and it's a monster closet with 30 of those mutants that throw giant exploding balls at you that insta kill you on that difficulty. I signed up for that, so I can't complain about the difficulty (I will a little - arbitrarily inflating health values isn't a fun approach to difficulty.), and paired with my earlier complaints about level design...
The enemies aren't that interesting? You have Dude That Punches You, you have Dude That Spits At you, the weird eyeball thing that opens doors, and the Floating MUtant Dude That Super Murders You With Energy Projectiles. And The Eggs That Are There To Indicate Enemies Being Spawned In And For Some Reason Take Like 500 Shotgun Rounds To Destroy.
Another point I'd like to make is the weapon modding? There's the idea here that Weapons are "Modular", Weapon CORES determine the functionality of the gun, be it a pistol, SMG, or shotgun. Barrels modify the Crit, Spread, and some other affects, Heatsinks cool the gun faster and allow more heat to be built up before it overheats. In reality, these are strictly linear in progression, if that makes sense. There's no player expression to making guns, no interesting designs, every higher tier barrel is a strict upgrade. Every higher tier heatsink is a strict upgrade. There's no barrels here that give you more crit, but more spread, or modify how a gun might shoot. There's no heatsink here that has a super high capacity, but low cooling. And the Cores only allow you to put as many points into them that are relevant to the tier - so you always use the same, or below barrels/heatsinks.
Despite all that, I still enjoy it for the most part. I probably won't revisit the hardest difficulty, though. I like the vibes. I enjoy the music, for what little there is, some of it has... pretty decently fitting vibes for how alone I feel in this game. The desolate districts still stocked and full of things as if everything had just come to a stop naught but a few hours ago. The occasional signs of struggle you see here and there, the few times the game employs a bit of mystique and hides things behind doors or barriers you'll never get across, a glimpse into a bit of story of a person within the world. The text logs that fill in details about the corrupt higher ups of the mars base. I wish the environmental story telling and such things occured more often, the tens upon tens of floors I've done might stand out more if they had anything going for them.
Hell, I even like what little voice acting there is in this game.
I'd take a thousand games that make the same mistakes on the path to game development and expanding the skill of game development than I would one more ♥♥♥♥♥♥♥ bit of AI Slop ♥♥♥♥♥♥♥♥. I'd take any of the stuff I'd complain about here, or anywhere else for that matter, just because it at least represents human work that people put into it. At least this is an honest bit of work. Some of the big indie hits all use that ♥♥♥♥♥♥♥ AI Gen Voice, or use Gen AI in concept art phases or designing things for them. I'd take a lot of weird little out the products, like this game or anything else, over people consigning their thought processes to ♥♥♥♥♥♥♥ *AI*. What's the point of concept art if you just get AI to make it for you, man.

I wanted to play this game before playing Mines of Titan because I wanted to get all the backstory. I feel like playing definitely gave me some backstory though it doesn't really feel like a lot of it gets explained until the end. Until then you do get some important backstory and a lot of notes about randos doing stuff around the facility.

One thing I don't get is why this Mars base has so many pool tables and slot machines. Even outside the casino. Which...why is there a casino?

I do like the combat to a degree. It feels like there's a lot of ways to go about it, but I stuck to a pistol/shotgun combo which worked pretty well.

Tech progression felt okay I suppose. The 2nd tier facilities have 10 floors and I feel like it's only like that to fuel both the length of the game and to provide more materials for crafting. Sometimes it just felt like a slog because of it.

Largely I do like the game. However...the last boss. I literally just gave up. After the 10th shot, I just gave up on that route. The dev does recognize the pillars had too high a health and did bring it down, but there's just so many and by the time I got there, I couldn't get any more mutant-related materials so making the drugs to keep myself moving was just out of the question.

If I could use an item and it would still get used even if you got hit then I could probably do it, but there's just too much going on.

Did I originally get what I set out to do from playing this game? Yes. Do I kind of wish I watched a video about the history (if anyone really ever made one)? Also yes. Still going to recommend the game though because I'm sure someone who is more into bullet hell games would love that part.

Compelling survival horror game that takes the survival part of it seriously. Interlocking systems of personal and map infection rates, hunger, thirst, sleep, slow heal times, stamina, semi-automated resource generation, map-scouring resource grubbing, research and crafting, and power management all combine in a pressure cooker where the clock is always ticking and you are always strategizing how best to use that time. It's criminal that this game isn't better known.

Funky little indie survival horror that you can put a decent amount of hours into.
It's a bit grindy with regards to resource management/weapon durability and I did have to look up some guides to figure some things out but overall its pretty fun.

Subterrain, developed and published by Pixellore Inc, is a demanding top-down survival horror game that blends intricate resource management with a persistent sense of environmental collapse. Set in an underground Martian colony that has fallen into chaos after a mysterious outbreak, it places players in the role of Dr. West, one of the few remaining survivors. Rather than focusing on action or spectacle, the game builds its identity around pressure—constant, layered pressure that forces players to think carefully about every decision they make.
What immediately sets Subterrain apart is the complexity of its survival systems. Instead of a handful of basic needs, the game introduces a network of interconnected mechanics that must be managed simultaneously. Hunger, thirst, fatigue, oxygen levels, body temperature, and health conditions all require attention, and neglecting any one of them can quickly lead to failure. These systems are not isolated; they interact in ways that create cascading consequences. Venturing too far without proper preparation can result in running out of oxygen, while exposure to environmental hazards can trigger additional complications that spiral out of control. The result is a gameplay loop that demands planning, awareness, and constant adaptation.
Beyond personal survival, the game extends its mechanics to the colony itself. The facility is not a static backdrop but an active system that must be maintained. Power distribution, oxygen generation, and temperature control all play a role in keeping the environment livable. Players must decide which areas to prioritize, often under limited resources, creating a strategic layer that goes beyond moment-to-moment survival. This broader responsibility adds depth, as the player is not just trying to stay alive but also attempting to stabilize a deteriorating system that continues to degrade over time.
Combat is present but secondary to the overall experience. Players can craft and use a variety of weapons, but encounters are rarely straightforward. Enemies evolve and become more dangerous as the game progresses, and engaging them without proper preparation is often a mistake. Success in combat depends less on reflexes and more on positioning, resource management, and understanding the situation. In many cases, avoiding confrontation or finding alternative solutions is the safer option, reinforcing the game’s emphasis on survival over aggression.
The pacing is deliberately slow and methodical, which may not appeal to everyone. Subterrain does not guide players gently into its systems; instead, it expects them to learn through experimentation and failure. The early stages can feel overwhelming, with a steep learning curve that requires patience to overcome. However, once players begin to understand how the various systems interact, the experience becomes more rewarding. Progress feels earned, as each small success is the result of careful planning and execution rather than chance.
Visually, the game adopts a minimalist top-down perspective that might seem simple at first but works effectively within its context. The underground colony feels confined and hostile, with dimly lit corridors and abandoned spaces contributing to a strong sense of isolation. The lack of visual excess allows players to focus on the mechanics, while the subdued presentation enhances the oppressive atmosphere. Sound design complements this approach, using ambient noise and subtle cues to reinforce tension without relying on overt horror elements.
Crafting and progression systems add another layer of depth. Players gather materials, break them down into components, and use advanced tools to create equipment and upgrades. Research plays a key role, unlocking new technologies that improve survival chances. This progression is meaningful but never trivial; every upgrade requires effort and often involves taking risks to acquire the necessary resources. The balance between risk and reward is a constant theme, shaping how players approach each new challenge.
Despite its strengths, Subterrain is not without its issues. The complexity that defines the game can also make it difficult to approach, particularly for new players. The interface and tutorials do not always provide sufficient guidance, leading to moments of confusion. Some systems can feel cumbersome to manage, especially when multiple factors demand attention at once. Additionally, the game lacks the polish of larger productions, with occasional inconsistencies that can disrupt the experience.
Ultimately, Subterrain is a game that prioritizes depth and challenge over accessibility. It offers a layered survival experience that rewards careful planning and persistence, creating a sense of immersion that few games in the genre achieve. While its steep learning curve and demanding systems may limit its appeal, those who invest the time to understand it will find a deeply engaging and rewarding experience.
Rating: 8/10

TL;DR: I highly recommend this game who likes to loot, hoard, upgrade and such. (Tip & Tricks at the end).
I don't know why I haven't posted a review yet, but I feel bad about it. This was one of my favorite games. Nothing shows it more than I completed all the achievements :) Fun fact: Permadeath was achieved alongside with Nightmare x) I loved the story too. If you can imagine and put yourself into Adam's shoes, any of the endings can hit you. At least it did to me :P
Anyway, because I'm not that good at writing reviews, I want to reflect on some of the points of the negative reviews:
1. Pacing: For me, the only "downtime" was when I wanted to max my pistol becuase that is the best weapon in my opinion. And I used quotation mark on purpose because while you are waiting, you can start clearing areas to prevent infestations or reactor raids. This will come in handy at the end when you place the final purification tanks in place.
2. Many people struggle with contamination. I never had an issue because the contamination pill works in a way that it slowly (higher tiers are quicker) heals your contamination. So, if you are hit by a mutant or drank from tap watar (but why?), then you just need to pop a pill and sleep. If you can't sleep, then just use the tram to speed up time.
3. I also see that many people complain about bad weapon damage, and so slow progression that at the end it is very hard to farm the high-end chips. Yes, you need to hurry if you don't want to bring 10 weapons with you to clear a single floor. But you can save a lot of time if you know how saving in the game works. I will explain it later.
4. Weapon degradation: Yes, it is there, yes, it can be annoying, yes, it can cause you to die. But, it is really not that hard to figure out that you need multiple weapons on you to counter this. The high-end weapons can really shoot for very long time. You can basically clear a fully infested area with like 3-4 pistols.
So, some tips & tricks for the end:
- The map "hack": As I mentioned, time is of the essence (at the beginning). So what you can do is to pre-explore the floors above the 1st one. What I mean is when you enter a floor, the game creates an autosave. So you just explore it casually, searching for chips and the exit. When you have what you want, don't go to the next floor, but reload your save. The map layout will be exactly the same and if you memorised the turns correctly, you can bash through the floor. This saves you ALOT of time, even factoring in the exploration time.
- Another map related tip is that the location of the chips is also fixed. You can find a map online where you can find which chip, but basically you can find 1 chip on floor 1-5, and 6-10. This helps you with the map "hack" because if you find the chip on floor 1, you just need to search for the stairs on floor 2-5.
- You can barricade the reactor room in a way that the mutants won't reach you ever. Basically, you need to pull most of the heavy stuff from the storage room or other rooms into the bottom right (or left) corner so they wedge agaist the wall. I recommend to experiment with the layout, but when you have it, it is very easy. Also, you need to take out all the reactor cores exept the one where the barricade is.
- Weapons: From my experience the tier list is the following:
Pistol: the king. When you have the barrel that has laser scope, then you should go to settings and set the aim drifting to maximum. This way you can target mutants across the whole map or corridoor. It is insanely OP.
SMG: Not that good for the player, but since the sentry tower in the reactor room uses SMGs, it worth to max.
Shotgun: perfect in early game, mediocre in mid game, and trash at late game. Highly evolved mutants has the potential to clap you, so getting close to them is not advised. I usually don't upgrade these, only for the meme and lastly.
Plasma Launcher: A double-bladed sword. Use it with caution. If you are careful enough, it is very devastating and super useful clearing up the floors in the endgame.
Other melee: meme. I kept one in case I forgot about the durability of my weapons.
- +1: I loved Marsmari supplement because it made the runs safe. You no longer open the wrong door :D
All in all, I loved this game and was very sad at the end. I felt the emptiness in the hallways and I missed even the mutants x)