One of my favourites so far for sure :) The mechanic leads to some interesting emergent strategies, like configurations of blocks that can keep the knight trapped for a while and dropping enemies down a hole in the floor to get them out of the way. I had two main gripes - I think that it was a bit too slow to move blocks around, and I feel like some levels may have benefit from a non-moveable block that would force the player into finding creative solutions to puzzles.