underrated or "not so popular" games

Heaven's Vault

I won it here on SG, and it was a joy to play, even if it has a few flaws.

Unloved

Unsighted. https://store.steampowered.com/app/1062110/UNSIGHTED/

Incredible metroidvania with complex combat and movement. Great replayability if you want to do boss rush mode or just speedrun, and a great time mechanic embedded into the story forcing tradeoffs. It's rated as Very Positive (94%) but I don't see it getting the love it deserves

Nex Machina. Never played a top-down shooter but the soundtrack and exceptional gameplay combo, plus the visuals, just made it a blast to play
https://store.steampowered.com/app/404540/Nex_Machina/

Desktop Dungeons Amazing puzzle/Roguelite/RPG good in short bursts, but also great for losing the sense of time completely.

Waking Mars Very interesting metroidvania/exploration game, with a great sense of progression and a nice mystery to unravel.

Avalance 2: Super Avalanche Great casual game.

Splasher
Sideway New York
GNOG
Ittle Dew
Ninja Pizza Girl

Impaler

https://store.steampowered.com/app/1948280/Stacklands/

Levelhead: Platformer Maker - 96% positive - 708 user reviews
The Void Rains Upon Her Heart - 100% positive - 487 user reviews
Copy Kitty - 98% positive - 267 user reviews
https://store.steampowered.com/app/361230/Super_Daryl_Deluxe/ - 93% positive - 192 user reviews
Glyph - 98% positive - 72 user reviews

Hard west
its like desperados with xcom combat and less rng

The council.
adventure game with slight rpg elements. consequences of your actions are not instant. and sometimes you see consequences after 2-4 hours.

killer 7

Hero Siege

https://store.steampowered.com/app/452570/Battle_Chef_Brigade_Deluxe/

If you love the Wii Play tank minigame you will love Wee Tanks :D

IDK how hidden this really is, but only 413 reviews and only 78% of being postive... I will take it... at least for underrated.

Minute of Islands
The story, Art and Music of this game are all amazing, I am sucker when you combine all 3 of these. Only part some might find it lacking is in the puzzles which is definitely not the games focus as its more story focused.

Daemonica (2005)
Detective adventure game in a medieval setting.The game is not perfect, but the story and world are well developed. Feels like reading a good book.
Too bad the sequel never came out.

Not very known, still updated often, for true RPG nerds.
https://store.steampowered.com/app/342610/HyperRogue/

if you enjoy restaurant management games, this is really good. it's really charming and fun overall
https://store.steampowered.com/app/375250/Pizza_Express/

Emerald City Confidential

True Fear: Forsaken Souls parts 1 and 2 (the final game in the series is supposed to come out either later this year or early next year)

Startopia, a sort of Dungeon Keeper management thing but on a space station.

Sacrifice, you're a bizarre wizard that summons weird creatures that sing and whatnot. It's a strategy game and It's awesome. Here's Mandalore's Review if you wanna find out more.

Thunder Force IV and Contra Hard Corps for Sega Genesis/Mega Drive.
Those games haven't got enough price imho!

Advent Rising
Two worlds I-II.
Silverfall
Binary Domain
Venetica

Paper sorcerer I would be very surprised if anyone had heard of this game before. It was one of the first game's I bought on steam a long time ago and I've beat it multiple times. I will warn the game has a lot of bugs (some prevent getting all achievements sadly) one of them game breaking but there is a fix too the game breaking bug I was able to fix it and beat the game. https://store.steampowered.com/app/263560/Paper_Sorcerer/

Going with "games that I think deserve more attention" rather than "underrated" because ratings are subjective, and my recommendations tend to have good ratings anyways. These aren't really hidden gems either, but maybe someone hasn't heard of them before.

Severed Steel - I guess it gained a bit more popularity with being in some recent bundles, but it still seems to fly under the radar for a lot of people despite being such a great game.
Hacknet - Okay, so not really a hidden gem, but a game that most people might overlook because of a generally "boring" appearance. This is a REALLY good hacking/puzzle with a surprisingly rich amount of "lore" if you can call it that (lot of files, logs, etc to read every time you hack into a new network).
Door Kickers - SWAT top-down tactical strategy game. I don't know how else to describe it.

Everlasting summer
https://store.steampowered.com/app/331470/Everlasting_Summer/

The best visual nover I ever played (However, I haven't played many of them)