The game I'm making is called "YATBBH" for "Yet Another Turn Based Bullet Hell" (as I imagine there'll be quite a few of those this Ludum Dare). I'm actually sort of hedging my bets, and have written it so that I should be able to tune it to be turn based or rhythm based, depending on how hard the puzzles turn out to be.

Here's a gif of where I'm currently at:

I do intend to add better artwork later (it will still very much be programmer art, though!)

Things achieved today: - major part of puzzle generator done (i.e. whatever's generated is guaranteed solvable) - rendering started

Tomorrow hopefully I'll be able to get some reasonable puzzles generated from this, and then handmake a couple of "tutorial" ones.

Also, code so far can be found here: https://github.com/jf89/ld41 (I've just noticed there's no license in there yet - I'll put in the GPLv2 at some point).

Hope everyone's having fun! I'm off to bed now as I'm exhausted ^_^