Yes, there's only one stage. A cutscene is supposed to happen before the level and after you defeat the boss, but it broke at the last minute. I'll add a note about that in the description. I apologize for the confusion. I'm glad that you find the mouse controls interesting. I was wondering if it would be better to use the arrow keys instead. The original idea was to have the mouse scheme for a mobile option, but I won't be going that route. I'll change the keys to what you suggested.
I noticed the infinite amount of energy when you hold the mouse button, but thought that it would be a nice little "cheat" until I got some of the other bugs fixed.
I really appreciate you playing this little game of mine, and offering your feedback. It was extremely helpful!