A palisade wall designs the land-border, rocks design the water-border. The snow falls continously, and the gorund is white, excepted the tiny road for Ugo. The sea is suddenly deep, and you wuold find a red button underwater: that's the way to unlock the gate for the freezing water of the Sea of Japan. There's a wall trough the rocks, too, that seems to be a dig, but it's very useless for the game.
Underwater you won't find any foe, but on the land there are more bombs falling than snowflakes: there are five or six bomber birds. Watch out!