I've been having migraines all week and my Internet is playing up, so this could be a dicey Ludum Dare for me. Nonetheless, I have the idea that I'll be trying to stick to: a bullet hell shmup where you can only shoot every ten seconds. This should actually make the game even harder than it sounds, because you can't kill the enemies before they fill the screen with bullets, so it's purely a game of how well you can dodge.

I have a basic prototype in place in TIC-80 and I'll start fleshing out the actual mechanics tomorrow.