This had such a classic arcade shooter feel to it, both visually and gameplay-wise. The music and visuals were spot on, and I really liked the background art too, especially the nice use of dithering. The boos looked really cool, and the fight itself was fun. I also thought the level design felt carefully crafted. You can tell a lot of thought went into the layout, especially with the branching paths where one route was clearly tougher but rewarded you with weapon upgrades. That was a really nice risk/reward touch.
Also making this in C from scratch is seriously impressive. It already felt like a very authentic old-school shmup. Great work. I didn't see any of the crashes you mentioned in the game page, but I did manage to crash my ship a lot XD