Beat all levels at one star difficulty or better.
Beat all levels at five star difficulty or better.
Beat all levels at the maximum difficulty.
Collect 50 powerups.
Play a four-player coop game.
Upgrade any stat to level 50 or better.
Die 100 times.
Have more than 55 enemies on the screen at once.
Kill 5,000 enemies.
Earn one billion total points.