Celeste $4.99 -75% - A platformer with 8-way airdashes. I'm sure you've already heard enough about how amazing the base game is, so I just want to take a moment to shoutout the incredible modding scene for more content. My favorites are Spring 2020 Collab, Strawberry Jam, Glyph, Conqueror's Peak, and Into the Jungle.

CrossCode $9.33 -65% (for base game and DLC) - Phenomenal action RPG. Combat is fast and explosive, dungeons are very obviously Zelda inspired but with way more puzzles. Packed with tons and tons and tons of sidequests, many of which put unique twists on the combat system to keep you on your toes. Make sure to grab the epilogue DLC.

Crypt of the Necrodancer $11.21 (bundle with DLC) - Rhythm game/roguelike sounds like the strangest mashup ever. But what's even stranger is just how well it works. It's just a matter of keeping 4/4 time, but forcing a steady pace forces you to think fast and not make any mistakes. Every death is clearly your fault as every enemy is designed to be beatable using only a base dagger without getting hit (and indeed there's a challenge character that forces exactly this), but dealing with swarms is where it gets complicated. I especially recommend trying to speedrun, playing for speed really makes this game adrenaline-fueled as you have to pace yourself judging how much time you can afford to gather items if you want to make sub-15 or sub-10. Danny Baranowsky's soundtrack absolutely delivers. Get both the Amplified and Synchrony DLCs.

Mega Knockdown $7.99 -20% - A turn-based fighting game that's fun for complete beginners to pick up and play, while still offering a lot of depth. Use this to entice your non-fighting game friends in.

Skullgirls $2.49 -90% base game, $14.83 bundle with DLC - Still the best damn fighting game of all time. Almost never not on sale, hell you probably already own this by now and may not even realize it.

Slay the Spire $6.24 -75% - Roguelike deckbuilder, basic idea is that after each combat you get to add a card to your deck, plus collect relics from elites/events/shops/bosses which provide passive effects. There's a ton of depth in trying to assemble the perfect deck one card at a time, resource management gets very complicated balancing what you need in the short-term versus what you want to take to the endgame. Tons and tons of possibilities, you can pretty much expect to never build the same deck twice. Oh, and did I mention there's 20 levels of hard modes once you think you've gotten A0 down? Also has a very powerful mod API with Steam Workshop support, check out Packmaster and Adventurer for my favorite must-plays.

Them's Fightin' Herds $3.99 -80% - Another great fighting game, been waiting a long time for this port to bring us up to a grand total of two good fighting games on Linux. Has a lot of really cool features like a big story mode with overworld exploration, a cute lobby system with cosmetics to collect and treasure chests to fight for, a dynamic music system that reacts to the fight, and even a semi-cooperative dungeon crawler mode. Has crossplay with consoles as well. Full review. Word of warning: Baihe DLC is very busted and banned from tournament play. Long story about how the publisher fired the entire dev team and released her in an unfinished state. If you buy the DLC, just get the other three characters and skip her.

Anything by Zachtronics - A bunch of different engineering puzzle games where you have to write code or build a machine to solve problems. Once you've solved the puzzle, you can see a histogram comparing your solution to everyone else's on a few different metrics, encouraging you to go back and try to optimize it further. I recommend Opus Magnum as the best entry point.