I have played a bunch of the games listed already so found some other ones on my steam list:
UnEpic was fun, I'm about half way through but haven't finished it but I had to stop playing games for the most part recently.
Not sure if it really fits but Toki Tori 2+ was great. I loved the way it taught you mechanics and the songs needed to progress and travel in the game because it is gated by knowledge of the game. You can do everything but warp right from the start of a playthrough.
I am looking forward to Ghost Song, it looks amazing, and I hope Chasm turns out well as it has been around for a while but not released.