No. The only playable characters in New Super Mario Bros. are Mario and Luigi. The minigame mode will also allow you to play as Yoshi or Wario but not Baby Bowser.
He is a playable character in the game Mario and Luigi: Bowser's Inside Story.
Bowser is not a playable character.
If you mean the games that involve defeating Bowser and rescuing Peach... Super Mario World (Playable with Mario) Super Mario 64 (Unplayable) Super Mario Sunshine (Playable with Mario) Super Mario 64 DS (Playable) New Super Mario Bros. (Playable in multiplayer minigames) Super Mario Galaxy (Save file icon) New Super Mario Bros. Wii (Playable with Mario or other characters) Super Mario Galaxy 2 (Playable with Mario/Luigi)
The first Mario game with Bowser was Super Mario Brothers.
Wario is not playable on New Super Mario Bros. However, he is playable on Super Mario 64 DS.
Dry Bowser is not in New Super Mario Bros Wii.
Baby Mario is a Trophy in Super Smash Bros. Brawl, but he is not a playable character. However, Yoshi, Mario, Luigi, Peach and Bowser are all playable characters.
You cannot play as Bowser in New Super Mario Bros. on the Nintendo DS.
Bowser Jr is in Super Smash Brothers Brawl but he is not a playable character.Instead he is a trophy.Trust me. I've completed SSE.
The boss is bowser.
Yes, he was a boss in New Super Mario Bros. for the DS and is a playable character in Mario Kart Wii.
Beat bowser, and huge bowser on the last level.