I have figured out how to upload it to itch.io via the app, so you can now download the latest updates from there! :)
I also have added a few small things as well as some minor fixes:

[ADDED]

- [F11] for manual fullscreen switching anytime during the game
- [New game] button! Now you can start a new game directly from the main screen.

[FIXED]

There would sometimes be an error after beating the boss of getting stuck and the explosion outro 
just playing over and over. I believe I have found the cause and fixed it, 
but please let me know if I missed something!! :D