Rogue

Metal Gear Solid 1-4. Ecco the dolphin? 😂 Good one!

I don't see them in the comments so: UFO 50 and OneShot.

Squarez Deluxe

Originally a paid DOS game and the developer is a cool dude who changed it to freeware. You can download it on myabandonware or archive org. Then grab a free copy of DOSBox.

In my view, it is the best shape packing game ever made, and it never really got its due, possibly in part to somewhat extra complexity, and partly from the time it came out.

You learn the ropes in the early modes, but you really need to play on EXTREME Mode. There are many different special pieces, and you decide how to move them in the playfield and rotate them.

There are mud traps and acid pits and missiles and bombs and traps. And you have to not only play the shape packing aspect, but you have to continually think about how to deploy these hazards, to your best advantage, or least disadvantage!

Over the years, I continually come back to this game, and I have probably sunk over a thousand hours since I was young.

Team Fortress 2

The best teamshooter game to date, endless copy cats that suck ass.

I think Bioshock 1, Inscryption, Portal 1 & 2(I believe that 2 wouldn't be so loved if we didn't already love 1, I like to think of them as a set), Silent Hill 2, Resident Evil, Nier Automata, and Okami.

I see Outer Wilds here but not Nioh 2, so I'm posting about Nioh 2.

Soulsian adventure with ninja gaiden blood, extremely high amount of endgame content, wild depth of character building, lots of avenues to increase your character's power with many "correct answers" to the question of "how should I make my dude stronger". Dropped a while before the most recent push for graphical fidelity with AI upscaling/antialiasing so it actually runs well on a large majority of steam hardware surveys machines.

It's hard early on, but provides the player with tons of options when it comes to progressing through stages and bosses, flexible movesets for each class of weapon and access to potent tools like Gun and turning into an enemy that killed you a dozen times the first time you saw it briefly. The endgame goes beyond replaying through the game into dungeons made of fragments of the stages and some more unique maps (The Abyss). There's a hefty amount of individual bosses to learn, and incentive to do some of the more fun fights in the game multiple times - a lot of which do not require a run back through a stage to get to them. The game does itself a service by breaking up gameplay into chunks with a world map you launch missions from, some of which are just a singular straight up boss fight.

Oh forgot. Best multiplayer game ever has to be Counter Strike 1.6, CS:GO and potentially CS2 in a few years.

There is no game: wrong dimension

Dungeon Keeper (with KeeperFX)