Nautilus Chase is the fifteenth level in Donkey Kong Land and the sixth level of Kremlantis. It is the only level in the game whose name neither rhymes nor alliterates. It can be unlocked when the Kongs collect a dynamite barrel from either Snake Charmer's Challenge or Chomp's Coliseum and use it on the overworld.
Nautilus Chase is an underwater level that is second and last one with a coral setting. The level is similar to Croctopus Chase from Donkey Kong Country, because Donkey Kong and Diddy Kong are chased after by a certain enemy through many narrow passages within the coral reefs. Instead of Croctopuses, the Kongs are chased by Nemos; these enemies start out as dormant but start to chase the Kongs when they pass them. The Kongs must swim quickly because the Nemos move fast. There are many Clambos, Chomps, and Fangfish in the level, often in small passages, where the Kongs can only avoid them narrowly. The last area of the level is large and maze-like, filled with extra bananas and Chomps. Nautilus Chase is one of the longer levels because it has three Continue Points and six DK Barrels.
Once the underwater level begins, the Kongs must swim between the coral and come up to the first Nemo. Although the level's first Nemo, it will chase the Kongs quickly, as they travel around the curving path, surrounded by walls of coral. Soon, the foe will stop, and the heroes will have to swim north, while watching out for enemies, such as a Fangfish. Shortly after, they will need to swim through a narrow path without hitting any Clambos or other fish. The Kongs must continue to swim around the twists and turns of the path, until they finally find the first Continue Point.
After hitting the icon, the heroes should keep moving through the level and watch out for more Clambos, until they meet another dangerous Nemo. This one will chase the Kongs as they loop up the path and begin to journey east. Eventually, though, it will stop, and they will only have to watch out for the usual predators. Once passing two Clambos, the next Nemo will come from out from behind a Fangfish and chase the heroes. As the wild chase progresses, Donkey and Diddy Kong will come up to another Continue Point.
Although they may have hit the Continue Point, though, the Kongs must continue to swim away from the fierce foe behind them. When they near a DK Barrel, the Nemo will, luckily, cease to follow them. Therefore, they can keep traveling through the level at a normal pace, as they paddle through the water between more coral. Soon, they will make their way up to another tight area, where they will have to swim around a few more Clambos. After this, the Kongs must swim north. Suddenly, as they make their way through the area, a Nemo will shoot up out of nowhere and chase the heroes again. The Kongs will have to swim around the corals and follow banana trails as they swim as fast as they can to avoid the strange foe. This Nemo will chase them for a long time, and to make things worse, there are some enemies in the way to attack. As they near the chase, the Kongs will pass the next Continue Point.
From there, the heroes must swim a little farther. After passing a few Clambos, the Nemo will stop chasing them. However, another Nemo will be seen hiding nearby, and it will begin to charge at the group for a while. Eventually, they will enter a maze or coral platforms, filled with a few more underwater foes. At this point, though, the Nemo will cease to chase them, and the Kongs can take their time as they make their way east. Soon, they will make it to the far end of the area, where they must travel downwards into a tight space and continue to swim between the curving path. Once the heroes dodge a few Chomps, they will enter an area with a portal. When they come up to it, it will suck them out of the level.
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