The art looks pretty good! Good job!
The Game is very difficult to control your character. Think it's because too much friction/deceleration when changing directions. Adding some deceleration/acceleration isn't a bad thing but the values are much too extreme and difficult to get used to.
This combined with also trying to dodge fast moving projectiles and objects makes it difficult to get into. It should be much snappier for a bullet hell type game. Being outside the bounds of the window = death doesn't make much sense and it takes away from the gameplay. I would introduce bounds into the gameplay and clamp the character into the box.
I would start by making the character easier/snappier to control, then introducing bounds the character can't go outside of instead of being outside the window killing you.