The first Digimon game I remember playing was Digimon World 4, and the second one was Digimon World: Data Squad. I remember playing as Dorumon in the former game, and not getting that far in the latter game, though I saw my brother get way further into the game than me.
It's much alike Smash Bros, except that instead of taking players out of the ring you just pummel them until they run out of health. Falling off cliffs does take some health out of you though. Also, platforms mean you can just hit and run away from the other players. Plus, there are constant item drops that can increase your stats temporarily. The game is not balanced at all but it's sure fun!