All Our Asias by Sean Han Tani
Sean Han Tani is one of the devs behind (wonderfully eerie top-down Zelda-a-like Anodyne), and if that fact doesn't have you furiously clicking the following link, then there's no helping you. All Our Asias is a free game that's a lot bigger and fuller than most, exploring Asian identity by putting you inside a blocky 3D adventure that looks convincingly like an early PlayStation game. It's the near-future, you see, and you're exploring your dying father's memories by plugging into a sort of virtual reality construct, a conceit that gels perfectly with the authentically dated aesthetic. I've only played a little so far, but so far this is excellent stuff. If you enjoy it, you can chuck Sean a few simoleons for some digital extras.
Bleeding Together, Dying Alone by René Rother
Bleeding Together, Dying Alone plays a little like Devil Daggers, if those devils were replaced with hordes of freaky spider monsters, and that dagger was swapped for a meaty shotgun. How long can you survive, as endless portals spew out spiders and other hazards in a dimly lit field peppered with makeshift graves? Well, you won't know, as this could maybe do with a timer and leaderboard, but nonetheless you'll be compelled to restart at a least a couple of times to show those blasted spider-beasties who's boss. (It's them. It's them who's boss, obviously.)
BlubBlub: Quest of the Blob by Girls Make Games
Created by a trio of kids (before being gussied up by some game dev pros), BlubBlub: Quest of the Blob is a silly, sweet, and surprisingly bloomin' difficult sidescrolling platformer. After a Kirby-like blob is kidnapped by a cuteness-hating scientist, and imprisoned in a trap-filled lab, you, well, you have to escape that trap-filled lab, searching for your equally squishy chum Blobby in the process. Much of the difficulty, I think, stems from the slightly odd controls (it's very difficult to find the sweet spot for the double-jump), and you'll need to try and master them, as a procession of slicey, acidic, or pointy hazards lies between you and delicious freedom.
30 Seconds to Midnight by NotBambi
It's 30 seconds to midnight in... 30 Seconds to Midnight, which is accurate if you replace the word 'midnight' with 'the end of the freaking world.' That's not a huge amount of time in which to do anything meaningful, but in this one-room Bitsy adventure, there are a number of different ways to spend your final moments. I won't spoil them, as that's the whole point of the game, but there are a few minutes of enjoyable exploration and repetition here.