I really like this game! I've played some other similar game that had multiple types of undo, IIRC, but this is a really nice realisation of it (that also fits well to puzzle script's constraints, which I appreciate !). "Over There" really stumped me! Some really nuanced behavioural differences. Some of the later levels I kind of stumbled through by, not so much thinking of what exactly would happen, but more permuting various elements until I stumbled across the right behaviour. It does seem there might be room for a bit more level design here.
I'd really like to add this to the puzzle script gallery - If you're interested in this, the one thing I'd request is either a puzzlescript.net (aka GitHub) hosted version of the game, or for you to add a link to the source code here (the gallery is meant to be a exhibition of puzzlescript games that I think are good, but it's important also that people can see what's happening under the hood so as to demystify puzzlescript a bit, should they wish). Either way, wonderful game :)