Fun time sink with to little to do.
The game itself is fine, I feel like if you had a week to fully flesh this game out it would be something really cool deserving of a front page mention. Maybe some upgrades health pick ups or whatever.
For a 72 hour challenge this is just about what I would expect, just a bit above average I'd say. Not that I could do better.
The black birds are a bit ridiculous for a second level enemy, but whatever.
All and all this is a great game, and of the challenge games this is the only one I'd actually like to see fully fleshed out at some point. Good job.