Hyper Light Drifter is an overhead pixel art Zelda-esque game. Aegis Defenders is one part Metroidvania and one part tower defense. Pixel art. It's extremely unique and good! Iconoclasts is an amazing pixel art Metroidvania. Owlboy is a pixel art Metroidvania. Children of Morta is an overhead Diablo pixel art roguelike. Crossing Souls is an overhead pixel art action adventure puzzle game. Hard to describe. Vane is a 3D realistic exploration puzzle game similar to Journey and Shadow of the Colossus. Extremely bizarre. But flying around as a bird has never felt more beautiful. Hard Corps Uprising is a sidescrolling shooter. Technically a Contra game....but with anime. Some of the best hand-drawn sprites I've seen in a long time, with 3D backgrounds and bosses.
I almost forgot about Axiom Verge!
Others worth mentioning:
Moonlighter Death's Gambit Dead Cells Blasphemous Strider HD Flower Wizard of Legend Songbringer Momodora Reverie Under the Moonlight
All amazing games! And never would have found any of them if I hadn't kept my eyes peeled and did a lot of research.
Axiom Verge is such a great game! Maybe somewhere down the line, say perhaps, ten years from now, people will start to rediscover some of these games again?
Some others I'd recommend are 100% Orange Juice (Mario Party), Environmental Station Alpha (metroidvania), Siralim (Pokemon), Mercenary Kings (Contra?), Town of Salem (Mafia/Werewolf), Grim Dawn (Better Diablo 3), Shellshock LIVE (scorched earth, tank), COGMIND (hard roguelike) ---