Super Mario World cheats for Snes
Strange Mario walk - Quickly hold L + R + X + Y + Up when the Princess is freed in the final level. Mario will walk strangely during the ending credits.
Climb and carry item - Stand next to a vine with an item. Hold Up and release Y to throw the object into the air, and quickly climb the vine while holding Y. Mario will automatically catch the item as it falls, and may continue to climb the vine.
Uphill Yoshi slide - Face toward a slope and press Down and L or R to slide upward.
Reuse P - Use Yoshi in any level with a P. Immediately after stepping on the P, turn around and eat it again. Yoshi will gulp it, you can then spit it out. When it comes out, the P will be full again.
Maximum lives - Find Yoshi and place a power-up that is not already in use in the item box. Enter a previously completed course and find a berry that is positioned just above Yoshi's mouth. Press Select to drop the power-up from the item box. Have Yoshi jump so that he eats the berry and the power-up at the same time. The game will freeze and the coin total will increase rapidly. Press Start + Select to exit the level after accumulating ninety-nine lives.
Alternatively, Go to the Forest of Illusion 1 with a cape, Locate the section with the caterpillars on the logs. Instead of killing the caterpillars, jump up and hold Y + B and try to land the first caterpillar on the head so it's hat falls off. Repeat this for the second and third caterpillars. After hitting the third caterpillar, return to the first caterpillar (his hat will be back on). Repeat this procedure until symbols begin appearing above the caterpillar's heads. Use this trick to collect coins, lives and points, but make sure you do not run out of time.
Finding the blue blocks - The Blue Switch Palace is found in the Forest of illusions 2. Play the water maze as far up and to the right as you can go. There are some diversions that lead you to pick up a life in the mid-level of the maze, but eventually you have to go up in order to find your way down. Work your way towards the bottom of the maze. If you are in the correct section, you will see a wall to the left that is rectangular and marked off by a line from the larger wall that sits on it. You can walk right through that wall, going left rather than right. The key to the blue switch palace comes into view very quickly.