New Super Mario Bros. Wii isn't a game for you to play by yourself. Sure, you could, but it's just not going to be the best way to extract all of the fun the experience has to offer. Instead, you really should try to corral some friends together for multiplayer, which is guaranteed to do one of two things: strengthen the bonds you and your three partners in platforming have established, or take those friendships you've worked so hard on over an indeterminate amount of time and stomp them like a lost, lonely Goomba.