It does not say on the page and I don't want to cheat by mistake,
I was wondering if you could use older unfinished assets/Build ideas/code work in the Jam game?
That's a good question. Assets made before the jam are fair game as long as you follow these rules:
1. You have the rights to use them.
2. Write which assets were made before the jam in your description.
3. Credit any assets you don't own in the description.
As for using older build ideas I don't see anything wrong with it so that's fair game too.