Cave Story/Outer Wall

The outer wall is the means of access to the Plantation, the step before the doctor. Unlike other maps, gravity pushes items to the left rather than downward.

The booster V2.0 allows you to speed through the map without too much difficulty, otherwise, you will have to climb the wall slowly.

Nikumaru counter
If you have the Booster v2.0 and brought Curley all the way through the Waterway, then you can collect the Nikumaru counter in the room labeled with clocks. Otherwise, a mysterious force keeps the chest closed.

The counter allows you to unlock a new theme song for completing the final area within six minutes.

Nemesis
Below the exit from the Egg Corridor, you can find a small dwelling. You need Booster V2.0 to safely enter, as it is extremely difficult to fly in and out with Booster V0.8.

This dwelling contains a few tiny people. The wife is looking for her husband who can be found in the graveyard. When you retrieve the tiny person and bring him home, you can optionally trade the sword for the Nemesis. You can trade it back if you prefer the sword, but the Nemesis is a more powerful item.

Climbing the wall
To proceed, you can climb the wall on the left side and proceed all the way to the top.

Optional chores out of the way, you can now advance. if you have a level 3 Mgun, this will be easy as killing Critters with a level 1 nemesis, and if you have the booster 2.0, it still won't be that hard, but if you have niether, well, this is going to be a pain for you. there's not much I can say about this area, but at the top is a way in. proceed back into the island undergrounds.

Entering the building
When you reach the top and enter, you will see a scared Minimga. Talk to him and he will reveal identify himself as Itoh. Talk to him, save the game, and head into the Plantation.