Mobage is short for Mobile Game. They're cell phone games where you "fight" other people who have the game. Winning typically gets you new items for your character. It looks like the controls for this one are:
5 key = attack
6 key = special move
7 key = evasive roll? "x 2"? Not sure what the "x 2" means...
I know the trailer shows a world map, but I wouldn't get your hopes up for this getting released outside of Japan.