How to undo a step? I think it's essential in this game :(

http://youtube.com/watch?v=1gfzkFCfnO8 Is this the intended behavior?

I got softlocked after finishing Only Sliding's last puzzle. Is there any way to undo that ? When re-entering my save, the playable block appears right after that puzzle, but my configuration doesn't allow me to go back.

Would love to play this one :)

The game does mouse acceleration by itself, even if it is off on OS level. Please remove it, or at least make it a toggle. It's very nauseating to play with mouse acceleration.