This amazing cereal was called Nintendo Cereal System and was produced by Ralston Cereals in 1988. The name of the cereal was based on the Nintendo entertainment system, and promoted two of the most popular games for the NES: Super Mario Bros and The Legend of Zelda.
The cereal box was divided in half, one side for the Super Mario Bros Series wich had fruity flavored Marios, Super Mushrooms, Gombas, Koopa Troopa, and Bowsers, the other side that was for Zelda series had Berry flavored Links, hearts, boomerangs, keys and shields, The cereal came with a sticker of a nintendo character and Nintendo "Power Cards" on the back panel. It also had offers to win NES Power pads or a Super Mario cereal bowl.
The cereal box could came with prices and tips for games
Here is a comercial of the cereal.