Warning Story can contain the ending.
In 2633, the Neo-Salamander Force, led by their mysterious leader Chief Salamander, travel back to 1973 to take out the Contra force, while the Earth defenses are still primitive. They end up setting base on the ruins of the Shizuoka temple at the Yucatán Peninsula in Central America. Bill Rizer and Genbei Yagyu, two members of the present day Contra team, are deployed by the Galactic President to travel back in time Genbei "Jaguar" Yagyu to stop them. With the help of Browny, the robot, Pliskin, a lizard-like alien, and Lance Bean, Bill's old partner, the Contra warriors manage to take down the Neo Salamander Force. However, Chief Salamander is nowhere to be seen. In the true ending of the game, it is revealed Chief Salamander is actually "Pliskin", who has infiltrated the Contra unit under an assumed name.
Contra ReBirth retains the same sprite-based side-scrolling gameplay as the series' earlier installments. The game can be played with the standard Wii Remote, as well as with the Classic Controller or a Nintendo Gamecube Controller. As with most Contra games, up to two players can play simultaneously. The player initially has a choice between two different player characters: Bill Rizer, the traditional Contra hero, or Genbei Yagyu from Neo Contra. Two additional characters: Browny (Tsugumin in the Japanese version), an cyclopus android shaped like a small girl; and Pliskin, a tall lizard-like humanoid alien, can also be selected once the player has completed the game on either of the first two difficulty settings.
The dual weapon system from Contra III: The Alien Wars returns once again, although the upgradable weapon system introduced in Contra 4 is not featured in this installment, the player's normal gun can now shoot in autofire once again. The power-ups in this installment consist of a Spread Shot, a Laser Gun (similar to the one in Contra 4) and a Homing Gun. Playing on the Easy setting will allow the player to always keep their current weapon after losing a life, a feature not available in any of the other settings.
The game consists of six stages. However, the sixth and final stage, along with the true ending, cannot be accessed when playing on Easy Mode.