One of the indie games they ran at AGDQ was a game called Perspective. I was asleep during it, but my sister watched it, and told me I needed to check it out. The game, not the speedrun. I did so, and while the game is very short it used a pretty neat mechanic and was quite fun.
The game is free and I'm pretty sure anyone who liked Portal or Antichamber has a pretty high chance of liking this one too. So go check it out!