Mercury

Access all worlds and levels:
From the main menu, select 2-player mode. Enter the initials as hg?
Quit back to the Main Menu. Start a 1-player game. In the world hub,
hold LEFT and RIGHT (shoulder buttons), then press SELECT.
This will unlock and allow access to all in-game levels.
Holding LEFT+RIGHT (shoulder buttons) and pressing SELECT
will re-lock all levels regardless of the 2-player initials.

Unlock Bonus Stages:
Place first on the high score boards for each stage.
Each one has it's own bonus stage.

 