It is a long time since I last mentioned New Super Mario Bros, but during the holiday I got back into it.
A week ago I completed the last level and my save got a second star (The first star was for rescuing Princess Peach).
Tonight I’ve got the last of the star coins (which didn’t give me a third star). I then noticed some warp cannons had flashing red circles; so I used the cannons and now have three stars.
Game Over!