I see some potential in there even though I'm not big on games that your character follows the mouse and you use the mouse to shoot. It just feels weird to me. Anyway... some enemies are so hard to kill it's pointless to even try. Actually this game is more about dodging than getting rid of enemies to get to the objective.
You need to add some sound effects. Some music would be nice too. Shop needs an upgrade. Boost in it are too random and you can get 3 of the same item that you can't afford for a few turns and it feels like it does nothing.