Gourmet Submarine Castle

Overview

Gourmet Submarine Castle is the fourth castle from Mystical Ninja Starring Goemon. It's located inside a submarine hidden under the frozen northern sea of Japan. The Peach Mountain Shoguns use it to store all the food they've stolen from nearby Festival Village. On the outside it looks like a giant submarine, but on the inside it's filled with gigantic food (mostly of Japanese variety). The only way to reach the castle is if Yae has gained the magic ability to turn into a mermaid.
 
 

Interior Layout

Unlike the other castles in the game, there is no main entrance marked by a simple door. Instead, Yae must turn into a mermaid and swim under icecaps to sneak inside through an open hatch. Since the castle is inside a submarine, rooms are tighter quarters than previous castles. New enemies patrol rooms with more potent attacks such as fire waves or becoming enraged after being struck. Aquatic enemies, such as robotic seahorses and spiny sea mines, can be found in the flooded sections of the castle that Yae must navigate with her mermaid form.
 
Many rooms have stepping stones made out of rice balls suspended over fire or giant hot plates. Slippery food bowls make for moving platforms while fox faced robots spew fire all over the place. Platforming is the main challenge of Gourmet Submarine, while navigating the flooded sections without getting turned around is a close second. The only unique item found in the castle is the Yae Bazooka. It allows Yae to use a bazooka with lock-on capabilities for a projectile attack. It's not required to beat the castle, but it's impossible to miss since it is right next to a key.
 
Despite the Mr. Arrow item (shows the location of the boss) there is no boss at the end of the castle. The last room is the submarine control room where Goemon and friends meet the Flake Gang member Poron.