If it was released in November for free on Steam, does not have any kind of pay-to-win and it's worth your time, then you can find it on this post. Demos/Prologues not included.
This is old school 3D aventuring at its best. Simple but intuitive mechanics, a variety of levels and a cool looking setting make the game an attractive choice when you just want to play through some fun levels.
From the Shadows
A local two-player cooperative platformer game with a little story. You can also enjoy it online through Steam's remote play feature. It is short enough to warrant compromise, so it shouldn't be too hard to find a friend willing to spend an hour in this.
This is one of my top picks. A great looking online Tower Defense, feature-rich with top notch mechanics and user interface. You can play it solo, coop, versus and even challenge yourself in ranked play.
Is It Wrong to Try to Shoot 'em Up Girls in a Dungeon?
If you are into the Dungeon ni Deai anime, this is your chance to play a horizontal scrolling shooter where you get to play as one charactger from the show's cast, along with a support of choice. The only caveat? It feels too short! Spanning only five levels, you'll still feel like you want more after you defeat each of their unique bosses.
The Floor Is Still Really Cheap Lava
This might look terribly whacky, but listen to me: the gameplay is ludicrous fun. Although the basic gimmick is simply avoiding these red tiles - which are supposed to be lava - the game throws in a lot of weird and interesting enemies along with crazy power ups and even a player versus player mode.
Got patience and nerves for puzzles? Astria might start easy, but its progressive difficult will eventually greatly challenge you as you get closer to the end of its 13 levels. There is even a boss fight at the end of it. It is fully developed, too: you are very unlikely to run into bugs while smoothly sailing under clean gameplay.
A masterfully done combination of traditional MOBA with base building and tower defense. This new, unique mix of genres is attracting players from both ends, so it should be easy to convince your friends to try it with you. I know it's gotten me pumped!
Beautiful, and I mean absolutely GORGEOUS action platforming. The air-dash and slice-through mechanics keep the game relaxing so you can enjoy the whole screen without having to get too preoccupied with combat. You'll probably beat it in like 10 minutes, though.
You're supposed to kill vermin. Breaking stuff is very satisfying. There's a plot and a dark twist. It's only 15 minutes long.
Although the game was probably built using Unity store items with very little customization, effort was most certainly there. Although it's a little glitchy, the end result is a different but fun 90 minutes long FPS experience.
Honorable mention: Cubiscape 2
Great for puzzle fanatics.