This game needs more zombies, people, lava, glass, ladders. People - shoot zombies and walk around but zombies can infect them to be zombies. Lava - Melts things like acid. Glass - Breakable by everything and fire proof and acid proof except lava. Ladders - Humans can climb up to get away from zombies.
I know a cheap way to beat boss 5. Just o up to it and sit right in front of it but a little to the left. Note: When the front of him blows up it will hit you.
sorry man in next update it will work promise