"Northern Sea" is the sixth level of Balloon Kid, and is also the third level to have a boss.
The level is completely made of ice, and features many animals that live in cold climates (Penguins, Walruses, etc.) as the enemies. The boss at the end of the level is the Snowman, who will throw his bucket at the player. While the bucket is off of his head, you must fall onto him.
- There is a secret Bonus Stage Gameboy that appears about a quarter of the way through the level, and the only way to get to it is to bounce off of a Bumper.