Thanks a lot for your feedback, I really appreciate it and I'm glad you liked it!
About that issue you had:
Did you play it in fullscreen or embedded into the website? Unity and WebGL don't allow you to catch the cursor, only in fullscreen for security reasons. I'm actually checking if it is fullscreen and then grab the cursor, and ungrab it if it's not. If you did play in fullscreen and it happened regardless that means you've found a bug in which case I'd be glad if you could tell me the browser you were using?