Nice concept! A few things are that Godots web builds can have problems with animations, which is what I think happened when the biscuit boy turned into a black square during shooting. Some changes I would make to take this from butter to BUTTER would be:
- Faster firing speed, more damage per hit
- Faster character and enemies
- Knockback of enemies
- Showing wave count
- Increased range of the gun and letting it hit multiple enemies
It's a really solid demo with a lot you can build off of it, hopefully you keep working on this and expand the gameplay!