Most jams allow you to, just make sure to give credit and when you submit, be sure to add that information so people know what you did.
Wrong. The rules state:
All assets and code must be created during the 7-Day time period of the jam
Doesn't that mean that we could actually take other art packs from itch.io if they were made in the 7 day period?
lol he didn't say we had to do it
