Backwater Bastion

Backwater Bastion appears to be an altered version of Unused Level 1, filename 1MARIO.bin. The level most commonly either replaces Bob-Omb Battlefield or Whomp's Fortress and can feature certain elements from both. The easy difficulty of the stage, among other things, resulted in people assuming that it was supposed to be a tutorial course, but was cut due to it's amateurish design.

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Backwater Bastion takes place in the middle of a castle-like area, similar to the small fortress found in Whomp's Fortress. There are two opposing towers found in the level; one on the right that looks like one of the towers from Princess Peach's Castle, and another one on the left, which has a dark blue stone texture. The two platforms that the towers stand on are divided by a blue slope that connects the higher and lower parts of the level, which makes traversing between them very easy and quick.

An interesting part of the level itself would be that there's a lake in the lower areas of it, which with the name "Backwater Bastion" in mind, seems to indicate that the structure is supposed to resemble a sort of combination between a fortress and a dam.

There seems to be no enemies found within the course, except for two chain chomps that guard the towers. However, defeating either of them doesn't reward the player in any way.

There are toads in the level that, when interacted with, give gameplay advice to the player that seems way too advanced for even the developers of the game to have knowledge on at the time the game was developed. For example, one toad explains the process of Backwards Long Jumping in detail, while another one tells the player about "MIPS clipping", an advanced speed running technique that allows the player to clip through doors.

Even though the level commonly replaces full courses like Bob-Omb Battlefield and Whomp's Fortress, only one power star can be collected in the level by climbing up the tower on the left. The power star notably also counts as a castle secret star.