Instructions
Select "Build Your Own Adventure" from the level creator menu, then select "Create."
Choose your treasure. This will be the object you're going after in your adventure, but it won't have any effect on the actual gameplay.
Choose your first level, designated by the square in the middle of the screen. This can be any level from the main game (including bonus and treasure levels), or any level you've created.
Choose two characters to use in this level, designated by the two circles. All unlocked characters are available for selection here.
Select a vehicle to use in this level. You can also choose "On foot," if you don't want to use one.
Select the next level, again choosing characters and a vehicle. Your adventure can have up to 10 different levels in any sequence.
Select "Save." Now you can edit or play the adventure at any time. To star the adventure immediately, select "Play."