Mini-Fiery Mario
If Super Mario touches Bowser and the hammer simultaneously, he will flicker as if he is about to revert to regular Mario. When Super Mario obtains a mushroom in the following stage, he will shrink into regular Mario. The next power-up he can get (assuming he is not hit first) will be a Fire Flower that changes his color and allows him to shoot fireballs while still small.
Alternate method to the 4-2 warp zone
On level 4-2 (an underground level), an above ground coin area and warp zone is reachable via an ivy vine/beanstalk. However, a variation of the 1-2 trick to get to world -1 may be used to reach the coin area in an alternate manner. Before the area where the vine is accessed is a long corridor with a lower corridor at the beginning of it. From this lower corridor Mario may be made to slide through the lower bricks in a manner similar to the -1 trick. (During the crouch-jump Mario's head must pass through the "?" block to the left of the opening to the upper corridor). After the slide, as in the -1 trick, Mario will be at the right side of the screen, ahead of usual play triggers. An experienced player with knowledge of the level can then manuever Mario (without dying or backtracking) to the coin-area pipe beyond the vine area. If Mario enters the pipe here, instead of being transported to the normal coin area, he will find himself in the above-ground coin/warp area.