If you don't mind me asking, could you explain the bugs a bit? I'm aware that there are a good few of them but I've struggled to recreate them to find the exact cause and fix it.
I don't really remember how to recreate them but the problem was some previous cycles didn't grab the cubes and/or stayed in the same position without moving.
I have a feeling a lot of the bugs are a result of my method of playing back the player's inputs, if I end up expanding the concept further I will need to completely rewrite that part most likely.