Tip: use chicken legs for skull collecting, they aren't strong, and they are very quick, you may also want to use chicken head for the sauce breath, it kill all humans and tanks who touch where it lands, perfect for keeping humans in the boundaries
Im either good at puzzles, or good at copying the walkthrough, I have all levels on par and level 17 and level 31 on star, if someone gets star on any other level let me know
After getting the boomerang, go to the top left of where you collected it and fire, there should be a small vent you can break open, you get an extra heart for it
REMEMBER: This is what happens when we lose most of our resources (-Zombies) And that's not too far away, maybe in 15-20 years (the population will grow a billion or two, trust me)
Tip for the boss: press down to fall down, trust me, you must use down key when on platform or you will get hit even more, tray and stay off the platform he's on