Well, maybe cave flyer is a bad description since there's no gravity.  But a turn-based Newtonian physics space-game where you fly around in caves.  I've been fighting with collision detection but I think I have it working now, so nearly three days left to add enemies and weapons.  I'm planning to keep that part relatively simple (but with a few hopefully interesting interactions).  I'm mostly relying on the acceleration mechanic to make it interesting, I guess.

https://github.com/JoshuaGrams/asctiiroid

Ah man, so close.  I have a couple of enemies (one that sits still and shoots at you, one that tries to bite you and splits in half when you shoot it), a few items/upgrades to play with, and it seems fun to me, but I need a couple more hours to finish chaining levels together and implement the scoring and...yeah, I'm out of time. Maybe if I had spent more time writing code and less time playing the game? Oh well, I guess this will be an 8-day roguelike. :-)