When you play as a monkey, not taking into account the surrounding area, the Ninja Monkey is the worst. The regular Monkey and the Cyborg Chimp are close, and the Brains is the best. This is based on size. All the monkeys have the same stats and view height. The smaller the monkey is, the better they are because they are harder to hit. Brains is the best because chunks of his body are cut out and his head can come off, making him even smaller. The Ninja Monkey is the worst because he has swords and items that you can shoot which hurts him. If the area you play in has a lot of pipes that give off steam when you shoot them, choose the Cyborg Chimp. Steam does not hurt him. If you play in a dark area, choose the Ninja Monkey because he is black. If you play in an icy area like Siberia, play as the Cyborg Chimp. He is the same color as the ice. If you play in a brownish area, choose the normal Monkey or Brains. They are the same color as their surroundings. Note: Sometimes Brains has a tendency to blend in with things that you would not expect him to.