Alternate ending sequence: Successfully complete the game, then defeat the new
Boss in the final level again. To view another alternate ending,
complete the game, then collect the red gem found in all of the
bonus 40 levels. Then, complete the final level to see a second
alternate ending.
Bonus levels: Successfully complete the game, then replay all levels
that you previously obtained a vehicle. Complete them to unlock
an upgraded version of the original vehicle that will allow you
to access new levels.
