replay system on a race car game
I don't see how that can be hard to save/restore, but maybe that's just me.Actually what *I* would do if the recorded data ever happens to be too big, is to indeed record the user actions (with their "date", rather than relying on the frame count), plus the very important part: the actual full information every N seconds to avoid going out of sync. Much like a mpeg movie contains reference frames for the very same reason.
This is the most sensible way IMHO, if size really matters here, which I doubt.