Contra 4 takes place two years after the events of Contra III: The Alien
Wars. After saving earth from invasion by Red Falcon, Bill Rizer and Lance Bean
are confronted with a new extraterrestrial menace: the terrifying Black Viper.
Joined by hard-boiled mercenaries Mad Dog and Scorpion, the warriors must once
again wage war against an entire army of invaders.

Refining the 2D side-scrolling genre the series established 20 years ago,
Contra 4 delivers pure action at a fever pitch as players jump, shoot, and dodge
oncoming hazards. Utilizing a new dual screen presentation, the action spans
both screens of the Nintendo DS, giving players the opportunity to battle across
expansive environments in which death can come from any direction. The use of
both screens for the game’s core action also allows for massive boss battles as
players try to seek and destroy the weak points of sky-high enemies. A first for
the series, Contra 4 introduces a grappling hook accessory that lets players
grab onto elements of the environment directly above them. Whether using it to
avoid oncoming dangers or attack from a strategic vantage point, the grappling
hook allows for new combat situations and dramatic set pieces that underscore
the game’s adrenaline-soaked pedigree.