Samus Aran runs the Contra Gauntlet
Aside from a heated rivalry with Ryu Hayabusa, Samus also has issues with Bill and Lance, the heroes of Contra.
So Bill and Lance set down a challenge for Samus. They challenge her to run the Contra gauntlet.
With the exception of the Spread Gun, and the Machine Gun, Samus has to use her own weapons.
Samus has to survive Contra, Super C (Super Contra), Contra 3: The Alien Wars, Contra Hard Corps and Contra Shattered Soldier.