I was quite pleased when I thought of the CTRL-Z :)
I don't think this could go much further, at least not with the CTRL+X command, which would break most later levels. I could cut (teehee) the command or introduce it much later though. I've actually just started learning pixel art (see the updated cover image for the game :) ) so I could use this as a case study.
Anyway, thanks for taking the time to play it and give feedback.