Cool game!
This game works really well as a bullet hell with ships. The controls are responsive, the enemies' have good patterns with their attacks and the atmosphere is well done.
There are some considerations to take for future games. Adding sounds could help to improve de experience. You can make your maps more recognizable, try adding some specific elements that help the player to know were he is located easily. The melee attack is slow and really limited, so it could be better to be compensated with some other kind of advantage. A color scheme could work too, when I got the plasma cannon I was unnable to know which bullets were mine and which from the enemies.
You did a good job. Making a game work from the basics is hard and you reached it great. Now you can add more mechanics and twists to the experience to make it more unique and fun. Keep doing it well!
Pd. The game crashed when I took the plasma cannon on the third level. Use this information in case it's helpful.