This is an awesome prototype. I played through it a few times. The pixel art is incredible. So bouncy and full of life. I love it.
The screenshake and camera movements are great too. However, I would probably be a bit more selective with the screenshake. It works great for when the player is shooting or gets hit, but I feel like it is disorienting when the screen is shaking because an enemy off-screen is shooting. Maybe limit it to only player actions or only things happening within the camera's view.
Other than that though, it felt really nice to play and looks beautiful. Keep it up!