This will only work once each on worlds 1, 3, 5, and 6. Also, there must be at least 1 Hammer Bros. on the map.

You must clear any level with the following conditions:

1) The number of coins you have must be a multiple of 11. (11, 22, 33.....)
2) The second digit from the right in your score must equal the ammount of coins you have / 11.
(So if your score was something like 0000045530, you must have 33 coins.)

To help alter your score, you get 10 points for every brick you destroy and 50 points (or something) for every second left on the timer when you clear the stage. If you met the two requirements before clearing the stage, "make sure the timer is on an even number" when you touch the goal.

At the end of the money ship, you'll fight two Boomerang Bros. Whatever you'd normally get from the Hammer Bros. will be your prize.