"A mix of Super Mario Bros and the Portal game"
Mari0 is a hybrid between Portal and Super Mario Bros. The mechanics of the game are apparently the same as the traditional Super Mario, a platform game in which you have to collect a series of items to earn points, avoid or kill enemies and at the end of the journey save a princess. But, and this is the important thing, thanks to being a Portal hybrid you will be able to use the magic gun characteristic of that game to open portals that will take you from one platform to another.
As a novelty you can play cooperatively with three other players as it has a multiplayer game mode that allows four participants to interact at the same time.