Played one level and all went well.

Now when I start, it says "Session complete" and immediately crashes. I've uninstalled/reinstalled multiple times. Also turned of cloud syncing.

This has happened to me twice. It seems to be due to savegame corruption. If you are very fast you can delete the saved game and then it should allow you to get back in. If that doesn't work, try to also load a known "good" savegame so it the game loads up in a "good" state. Good luck!