Bravo! Feels like an old Nitrome game. I like the way that new capabilities both allow exploring farther, and allow new kinds of puzzles. Having multiple puzzles available at once meant I could take a break if I got stuck on one.
I'm not sure I solved Back Up an intended way, or if I found a bug or inintened interaction (ROT13-encoded, since itch.io's comments don't seem to have a spoiler tag):
V jnf noyr gb znxr gur oyhr oybpxf nccrne bireynccvat n onggrel oybpx, gura chfu gur onggrel oybpx bhg sebz haqrearngu gur oyhr oybpx.