New modes, characters, and more can be unlocked by completing various tasks.
- Character color change option - You must get four gold skulls.
- Tower of Nana Co-op Mode - You must get six gold skulls.
- Commander Video - You must get eight gold skulls.
- Lost Levels Mode - You must get ten gold skulls.
- Counseil's Duty Free Shop - You must get 12 gold skulls.
- Sugimoto - You must get 16 gold skulls.
- Juni - You must get 18 gold skulls.
- President Thompson - You must get 20 gold skulls.
- Zombie - You must get 23 gold skulls.
- El Testigo - You must get 26 gold skulls.
- Curly Brace - You must get 30 gold skulls.
- Antarctica Temple - You must finish every Ukampa Ruins level.
- Antarctica Temple (access for all characters) - You must watch the "True" ending.
- Tina Hawkins - You must finish Ukampa Ruins.
- Jim Hawkins - You must watch the "True" ending.
In the scene after you finish World 1, Aban mentions the "Poko-mum" temple and uses the phrase "Pocket Monster," the Japanese name for Pokemon.
To get the "True" ending, you must have the Key of Serpentis. Take it to level 10-7: "Jokulkyrkja" in Antarctica. There is a platform there with a serpent symbol on it. Jump onto the platform to enter a boss battle. To defeat the boss, you must hit the crystals on the ceiling with knives, which will break apart the dragon platform.
Key of Serpentis
The Key of Serpentis is in Level 2-1: "Rush Into the Ruin" in Ukampa. To the right of the temple's exit, you'll see a block with a key on it. If you have all the gold skulls, you'll be able to remove the block and enter a new area, where you'll find the Key of Serpentis near the center.