Thank you for the nice comment!
I will look into locking the cursor in the game window, or detecting the mouse outside of the window, but I am not sure if this is possible on the web version. Feel free to share the suggestions, I appreciate all feedback :)
You're right, I have planned more levels, but they will take some more time as they will be more unique. Some more themes as well, but that will be for the future. Thank you for playing !