Yipee, we've enabled Steam Cloud Saves! Hopefully it doesn't break horribly.
If an existing save doesn't sync to the cloud, just load into it in-game, and toggle "Unlock Everything" on and off, or something else that'll edit the save file. Steam will notice and sync it properly.
We're constantly looking for feedback and bugs - you can either post them here on Steam, or join our Discord for much faster reply times.