Suggestion: two seperate hands, one for attack and one for movement, would benefit this system greatly.
I would also suggest adding "ghost motions" to bullet paths when planning your routing, as bullet paths are currently somewhat hard to understand right now.
To elaborate on that, I mean have a ghost of the action you're about to take loop in front of you, and if it intersects a bullet that will hit on that path, it plays an animation of your ghost dying.
This wouldn't reduce the difficulty much besides providing more feedback on planning, since the core difficulty here is more based around foresight and not getting yourself trapped in corners. Fights like the final boss are a fantastic showcase of this, since that fight is both chaotic enough to need such a feature and one of the better designed dodge-loops in the game.
Designing around pathing puzzles like that will be an excellent way to flesh this game out.
If you need design help or pixel art consider me enthused with the project, I'm more than willing to contribute.