Here's an section of the nintendo power article: "The news today is Mario and Luigi's long time rivals, Wario and Waluigi are getting their own game for the nintendo 64! The game is in a very early stage right now, and like Ocarina of time, re-uses the same game engine as Mario 64!" this implies that the game most likley plays identically to Mario 64 however the article later retcons this by stating "Wario has all his abilities from the hit wario land series, and Waluigi has water powers, to contradict Mario and Luigi's fire power's" This implies the game has different physics, and interestingly enough, a powerup system. The screenshot featured also depicts a very simplistic level which might be because of this, qoute on qoute, "Very early stage" that the game is in. This might also be because of the more traditional platformer style the game is hinted to be going towards.
No other information is known about the game, except some small tidbits about the skyboxes. The grass levels, all though not clear due to jpeg artifacting, Reuses the skybox from Super Mario 64. However the lava levels have original skyboxes.
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