[dr_zoidberg]

That doesn't solve login in from a different device. And if you cleanup cookies for whatever reason, you lost the progress. So no, cookies don't solve the same problem as a user account (with login from a "trusted" provider) solves for saving the state of progress by a user on this game.

[Spooks]

Maybe allow both options for people who want to keep their saves across multiple devices and one for users that use the same browser. It is a pretty trivial thing to do.

[bduerst]

They already do.

[enedil]

That's a game, an exercise for several nights