Cyborg. YAH
this game was cool dude, the trick to killing bush is to get as many health upgrades as u can as u play, and then once you get up to him go to one of the holes in the ground in the level (with the health pack in it) and crouch down once he comes after you, he will start twitching since you not supposed to be below him and then take the laser minigun and shoot up, the the sides of the hole prevent most missiles from coming in the hole, however some will hit you so u got to have a lot of health so keep on firing and firing till you kill him and if you are low then go to another hole and grab the other health pack there I LOVED THIS GAME IT ROX
Beat the Boss 
Paper Mario World