Giga Bowser Rampage. You play as a Stronger, Slightly Larger version of Bowser but using the Giga Bowser sprite. You get 1,000 HP to defeat 100 enemies in Waves. Each wave has 5 CPUs coming at you at one time. There are 10 waves, each wave giving the CPUs an increase in health with 20 HP given each wave, meaning that the first wave will start with 20 and the 10th wave will start with 200.
I basically took All-Star mode and Multi-Man Smash, added Giga Bowser, and came up with this.