Thank you for checking out my game!
And yes, you're absolutely right. If I hadn’t run out of time, that was exactly the original plan—a selectable option to disable the flashes and a progressive difficulty scaling system for the bosses. In theory, all of them can be taken down, but you have to maneuver very skillfully towards the corners.
By the way, your opening comment made me laugh—the answer is: coffee in any amount, and sometimes a little beer! 😆