I wish you can have CPU vs CPU vs CPU vs P1
Instead of having just two players vs eachother and no one wants to join, you should have all 4 players vs eachother and they eat bigger things. But when you press the -> and <- to start you should choose how many CPUs you want in the game. And then if a freind wants to join they can press the D and A or etc. And when that freind comes it, it should pause the game and say
"Here comes a new challenger!!"
You should also have an observer game where all 4 players vs eachother CPU vs CPU vs CPU vs CPU just incase.
Nice game though.