Toxic Crusaders (Genesis)
This game has a hidden level select.
Toxic Crusaders is the environmentally-friendly game based on the anti-nuclear kids' television show based on the gory film series by Troma.
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When "Press Start" appears on the title screen, hold A on Controller 1 and press Up, Down, Left, Right on Controller 2. A sound effect will confirm success.
Enter the options menu, and the level select numbers will be located at the bottom of the screen.