[iainmerrick]

One nifty thing you can do with snapshots in games is use it for save/restore/undo.

See for example the Z-machine used for interactive fiction, and its younger cousin Glulx: https://www.eblong.com/zarf/glulx/Glulx-Spec.html#saveformat

(Apart from that, I’d note that Glulx and the Z-machine are both terrific examples of detailed VM specifications. Glulx is impressive because it was built by one person, the Z-machine possibly even more impressive as it was reverse-engineered by insanely dedicated Infocom fans.)