Sure could. That's what stopped from building this in the past. I wanted to be able to go forward and backward and hop around to any frame. Turns out, that's a much bigger problem than just playing it forward. Essentially we'd need a perfectly functioning Undo counterparts to every commend we issue.

Now that it's built, I'm not so worried about the lack of a rewind button. If I get another free morning, maybe I'll look into it.

It's probably not the best way to go about it, but couldn't you implement that by just cutting the delay to zero and drawing from the beginning until the requested frame? It probably wouldn't work well if you wanted to step through the page backwards, but for just cutting to a specific frame it seems like it aught to do the job with minimal extra coding.

That's essentially how we do snapshots now. You can look backwards until you find something that clears the screen or loads a new page, and save some work by just drawing from there. So yeah, jumping to a frame isn't too hard. You just run the risk of melting something if you try using that technique to reverse the playback.