Magirune 2

Magirune is a puzzle dungeon crawler reminiscent of early PC games like Chip's Challenge. It's grid-based, so there's some sokoban type challenges involved, but those take a backseat to what I consider the star of the show - which is the blended combat puzzle system.
In a typical dungeon crawler or metroidvania, the major upgrades in or between the dungeons are what serve as the keys to unlock new portions of the world and prompt backtracking. Magirune still does this, but in addition every dungeon has its own meta-progression in the form of XP-based combat. In order to reach key rooms or switches, you need to farm enough XP to become strong enough to kill tougher and tougher monsters. Enemies require a fixed number of hits to kill based on your character/weapon level, each hit causes a fixed amount of retaliation damage, there is a fixed number of potions in the game, and there is a fixed amount of XP to be harvested - but enemies respawn between rooms. Since you only get XP on the first kill but healing is finite, you have to strategize how you are going to move thru the dungeon to most efficiently conserve life. This makes the combat simultaneously the only way forward but also something that has to be approached cautiously. You can't haphazardly kill everything in your path because you might have to trek back thru that area later, at which point you've already expended your potions. But becoming stronger will open up new paths and make the backtracking less costly because enemies can be killed in fewer hits.
This is a formula that comes all down to execution. If the level design is too simple, then moving forward is a tedious, riskless, linear process. But Magirune is VERY competent in its design - you will frequently have to stop and think and reference your mental model of the dungeon. Not just to save time in aimless wandering, but to survive. And the difficulty curves well, where new mechanics are gradually introduced to ramp up the complexity as you yourself grow more competent. We're not talking Baba is You or Stephen Sausage Roll level sorcery, ofc, but it is surprisingly well designed.
My recommendation is to play Magirune 1 (which is free) on the Normal difficulty. This gives 1XP for repeat kills, which adds a forgiveness mechanic for mistakes / careless planning but can be exploited to trivialize the puzzle element. If you like it enough to see that experience thru or close to the end, then pick up Magirune 2 and play on Hard, which is true finite XP and IMO the ideal way to experience this game. The combat puzzling is what makes this shine.
Magirune 1 is a bit rougher around the edges - in hindsight it feels more like a POC for the finished product of Magirune 2, but really that's a completely viable development path and it being a free download jives with that. It's competent in its own right and is uniquely aggressive with key conservation esp in the early game, where you can straight up softlock yourself. It's intentional - the game warns you and has a built-in dungeon reset option, but 2 seemed to be much more forgiving with the keys in favor of a longer, more robust adventure. 2 also has an NPC that can give you a single potion whenever you are completely exhausted. You can probably softlock yourself in 2 if you muck up bad enough, but it's going to be harder.
Lastly - for anyone who does pursue Deathless Hard mode, the teleports cure poison. The game does encourage you to use them liberally (they can be a key part of the meta navigation, esp in 1 where it feels expected) but the "cures poison" has to be intuited and can save big on potions in the early game, helping to avoid a dead run.

good puzzle elements, still feels like an adventure despite it mainly being a resource puzzle, and nice eastern eggs

It's good and worth $5 for sure, but despite being dramatically longer and more loaded with gimmicks, it does feel less substantive than the first game. Magirune 1 was a VERY tightly designed game, and required some careful planning and likely a few attempts to optimize your path and survive for the true ending.
This game is much more open ended with multiple required and independent paths, and is much more generous with resources to the point that it's pretty brute forceable on the first run, even on Hard. I never really felt like I was on the edge of my supplies like I CONSTANTLY was in the first game. I never once ran out of keys or really ran low on them at all. The moment you can break barrels you get flooded with all the potions you'll ever need, even if you never do the sidequest that will just give you freebies if you run out. By the end of a Hard playthrough, I had almost 20 potions and a couple dozen keys left over that were only used on the final secret in the game. Compare to Magirune 1 which has very few spare keys at all, and an optimal run will literally have you down to your last few HP by the time you get the sword.
This is still a recommend, just be aware it's much more relaxed and far less of a puzzle to survive.

Clever puzzles, core mechanic used to its fullest, resource management, this game does right what it tries to deliver, nice dungeon crawler, but it can be slow at times, which can be frustrating, that doing backtrack over and over again can be tiresome and time draining.

Nice if you like exploring pixel dungeons. There are a few puzzles, and maybe 3 of the sokobons were hard. I looked up an answer for one. But mostly it's fun exploring with moderate challenge.
Apparently this is a "Tower of the Sorcerer" clone, and the genre was huge in Japan. I'd never heard of it. So it's not entirely original but it's still done well.