After getting hit I couldn't go to the menu the progress bar just got stuck. So this review is a bit short sighted, I'm sorry.
I feel like it would have been better using the mouse by traveling in its direction it would have given an extra layer of control since the player could also choose when to fire, and if you wanted to keep the delay between shots then adding a cool down was an option, that would still give you an extra button to work with. The unlockables look nice but I couldn't really do much without crashing so again I'm sorry.