Zombies Ate My Neighbors and Ghoul Patrol (UP)

Using the Password CP4V you can fight this boss right away with the starting weapon, 2 extra lives and a medkit, the starting weapon is pretty weak but can be fired much faster by shooting the boss while up close to it so aim to do that as much as possible, if you die you get a few seconds of invincibility where you can spam attacks right on the bosses too.

Nice and easy fight, avoid the jump attack by walking left/right, try to find the safe spots from the turret attack and just spam shots on his legs, if he jumps back he will fire a laser straight down 1-2 times, really easy to avoid and that's pretty much the entire fight.

Ghoul Patrol - Robot Boss - CP4V

I tried every password known for Ghoul Patrol. It turns out some passwords got switched. Input the following password CPAV to face Robot aka the only decent boss fight in the game. Very quickly you can memorize how he fights to take down.