World 1-2 takes you underground. Be wary of the Buzzy Beetles, which are immune to fireballs but can be stomped. The key to this level is finding the secret Warp Zone. Progress through the level until you reach the area with multiple moving platforms. Instead of taking the normal exit pipe at the end, jump onto the ceiling above the exit pipe. Run along the top of the screen to the right. You'll find a hidden area with three pipes. The first pipe leads to World 2, the second to World 3, and the third to World 4. Using these warp zones can significantly shorten your playthrough, especially if you're aiming for a speedrun. If you miss the warp zone, simply take the normal exit pipe to World 1-3.
