On Wii, when you play with more than one person, you can die and keep going, as long as your parter's dead, or you partner can die while you're alive, as long as you don't run out of lives, you can make it to the end having died a bunch, without having to start over. Plus if you were to run out of all your lives, you lose every level you've completed in that world... so it's nice not to run out