This game is utterly amazing. Probably one of the best in the jam. The graphics and music are awesome, and the gameplay is smooth and compelling. I only have a couple of suggestions. The cover image as the main menu is honestly not that attractive. I recommend a custom one that shows the action a bit more, and that beautiful pixel art. Also, it wasn't very clear that I was supposed to get into the helicopter. I died plenty of times and was ready to quit before I saw "Enter/Exit Choppa" in the controls settings. I recommend a tutorial.
Other than those two points, this game is absolutely amazing. Keep up the good work!
edit: Also, the game occupies only a tiny space on my screen. It would probably be difficult, but couldn't you scale the game up to the size of the screen? That's what my game does