World 4-1 features many cloud platforms and introduces Lakitu, a Koopa Troopa riding a cloud who throws Spinies at Mario. Lakitu is a persistent enemy; if you defeat him, he will eventually reappear. Fireballs are effective against him. There's a hidden 1-Up Mushroom in a block above the first '?' block you encounter. Jump on the '?' block, then jump again to reveal it. Navigate the cloud platforms carefully, timing your jumps to avoid falling. The Spinies thrown by Lakitu can be tricky to avoid, so try to defeat Lakitu quickly if you have the Fire Flower. The flagpole is at the end of a series of descending cloud platforms.
