Cryptark

This is a hidden gem in the limited time free games. This sci-fi action game actually has more strategic elements than actions. The key to success is to make good plans. You can pause the game anytime and take your time to think. So the game pace can be either fast or slow, up to you.
While the default difficulty is quite challenging, all achievements can be obtained in easy mode and not hard to 100%.
The overall experience is very good on steam deck.

Roguelike shooter with the ability to create a strategy. This game is not for everyone and personally I don't think I will ever be able to finish it given the difficulty. It was given to me as a gift and I was happy to try it, but of my own free will I would never have bought it. My rating is 6/10 the price is really too high.

Simple style and good music. Fighting is fun. There is some challenge here too. It is good game!

This is a really enjoyable roguelike space game, reminded me of Heat Signature a little bit. The gameplay loop is rather simple: you need to enter the spaceship and destroy its core to complete a mission. As difficulty increases, so does the randomly generated spaceships' size and complexity - more and more systems are added that sometimes create quite a puzzle to solve, namely which systems to take out in which order and which route to take.
There is a decent variety of weapons and enemies, and two main game modes: Campaign (with a time/money pressure for each mission) and Rogue (no time and money, but your weapon loadout, ammo and health persist through each mission). There is also a Coop Campaign mode, but since I didn't play it, I'm not sure what it's worth. Rogue Excavation is just a single and somewhat quick mission that most likely serves as the game plot wrap up.
Took me a little more than 10 hours to 100% this one and to be honest, I can't say that the learning curve is THAT bad (saw plenty of "OMG this game is so hard" comments and reviews). The shield is probably the first thing you'll need to be aware of (save your HP), then energy weapons (endless ammo, but need recharging), then melee weapons (deal with anything but larger targets), then everything else.
However, either accidentally or on purpose, the dev team made the second mecha suit unlockable just for 2 artifacts - Rook - broken in the worst way possible. So if you are looking for a challenge, make sure to skip it and pick another mecha suit first. If you just want to complete missions and pew pew everything, Rook is the way to go. Its built-in special ability makes you completely invulnerable to anything; elite units, mines, nuclear explosions, swarms, alarm lasers, literally anything can be tanked straight with your face. You can't move or shoot while shielded, yes, but that's hardly an issue with a bit of timing: shoot - shield - shoot - shield - move - shoot, and so on.
Can easily recommend Cryptark for a certain number of evenings. Also, the OST is sick - try googling this: d1-3B Rigilkent z8-8q!

Exploring the ships and planning out ur movment is pretty cool. Managing your money is pretty easy though you can save money using energy weapons or melee attacks. The end boss ship is super hard but I was able to win after the 3rd try. Very cool game

A great combination of Gothic Cyberpunk style, fast action, strategy, and dashes of comedy. Different playing modes and mobile suits give a very different playing experience, and the music is rad and appropriate to the creepy, borged out enemy.

Infiltrate ships. Steal artifacts. Very fun game. Reminds me of Heat Signature. Great assortment of weapons and enemy types. It was a little tough at first, but after unlocking the first suit, the game got easier. The final Cryptark ship is significantly harder than the other ships so don't expect the strategy of the first few ships to work on it. The Cryptark requires constant movement and serious firepower. Finding tech power ups and saving money early game is the key.