This time around, there won't be a theme. I've changed that moving on for future jams.
The jam is about creating a game that has gameplay that lasts around a minute. This isn't like the Zero Hour game jam!
Generally, in the spirit of jamming, the game should be developed during the jam period, otherwise there's not much point!
I'm not sure what you mean about limitations - feel free to run any things you're thinking of by me here!
You can find more details about the rules here: https://itch.io/jam/one-minute-jam.
Hope that helps!