Interesting idea. The spawn rate of enemies seemed overly small. I would sit around doing nothing for a while without any spawns, I think I saw 3 enemies after playing for 5 minutes.

Additionally, the music is very loud and the options slider wasn't saving the volume.

This is a cool concept but I feel that there needs to be an incentive to keep the backpack close to you. Maybe the backpack attracts the orbs to you or makes you faster, but unable to shoot? I got very little enemies spawning while I played, so I'd increase that too, if possible. The visuals and geral presentation were really good, so I believe that with a bit more polish this could be an awesome game. Keep it up!

I couldn't shoot when I had the backpack in :( I think this is a neat concept, my team did something similar but with a boy and his puppy. give it a try? You can pet the puppy!!