World 4 (Super Mario Bros.)

World 4 is the fourth world of Super Mario Bros.. This world once again takes place in daylight. This world is the first world to have Lakitus, Spinies, and Buzzy Beetles. This world is the last world to feature an underground level.

World 4-1
Right after the first Warp Pipe encountered, a Lakitu is found in the sky tossing down Spinies on the player. The player can jump on top of a brick in order to jump on the Lakitu (or throw a fireball at it) and defeat it. The player must avoid the typical gaps in this level, however, Piranha Plants, Lakitus, and Spinies are the only enemies encountered in this level. The easiest way to complete the level is to run as quickly as possible to the end in order to avoid being attacked by falling Spiny Eggs (Spinies).

World 4-2
This is the second and last underground level in the game. This level is drastically more difficult than World 1-2, for it featured cramped areas full of enemies, large gaps, high pipes to overcome, and the addition of Buzzy Beetles. This level also features secret warp pipes to World 5, World 6, World 7, and World 8 (the final world).

World 4-3
This is yet another level set at extreme heights. Moving orange platforms are once again seen, as well as Goombas and Koopas. The tree platforms are yellow with red spots (the only level to feature this color scheme).

World 4-4
This final level of world 4 is a castle level. It features the typical firebars, podoboos, and another False Bowser, but it also features a few sections that are a puzzle; These sections must be walked through in the right patterns in order to move on to the end, making this quite a difficult level. One the player defeats the False Bowser, the player finds a Mushroom Retainer once more, rather than Princess Toadstool, meaning the player must go on.