Great start to a game! Here are my suggestions.
Use different loops especially for the longer levels.
Fix the bug where the poop rolls.
Fix the bug where sometimes when someone is hit they stand back up.
Do not allow the player to fly out of bounds.
Not sure if it was a glitch or my horrible eyes but I could never find human 10 on level 3.
Make listening to humans an objective.
And ultimately keep working on this because it is great!