Soon game jam will start and i can give you one tip is that i will play for 2-5 mins games. You can make longer games, but more polish and shorter are better then long ones with more gameplay, but less polish.
You can make assets already even the game jam has not started and prepare, but do not start making games yet!
Btw thank you for 30 joined people for the first game jam! 馃敟馃帀
Good Luck! 馃帀