Great game. It's in a very polished state for a game jam. The sound effects and art go well together.
I'm personally not a fan of moving and shooting at the same time with the mouse - it makes it hard for me to process in real time what I need to do and in the latter stages of the game I'm just moving around and hoping my bullets hit something.
The system works well in the earlier stages when there's less enemies/stuff going on, so I'm able to process if I want to keep shooting at a target, or avoid bullets.
I've got no strong suggestions on how to handle this, but maybe have a targeting cone in front of the player and allow bullets to home in on enemies in this cone?