Wow this is a solid game! Cool mechanic... in the end, I was only able to get 4 crystals although I really enjoyed this puzzle/metroidvania game. The writing was simple and combined with the music, it created a very cool scifi aesthetic.
The one thing I wish is I could just rewind the game a few moves instead of having to completely restart, though perhaps this is part of the challenge of the game :)
Great work!