Don't start making anything for this jam before it starts!
Generally easier games will do better, you want more people to be able to pay more of your game ideally. Bullet hell doesn't have to be difficult 😁
And the theme will be a single voting category. It's mostly there to address blank canvas syndrome more than anything, so unless you care about getting the best score in every category (you shouldn't care about that) you don't have to follow it. We're more relaxed than most jams about that!