The Cartridge is on top of this box. Inside The Loop, resembling the P.T corridor, is Player four’s Cartridge. You need to continue playing through this sequence as you normally would.
How do we know? It's all thanks to a custom Sega Genesis cartridge. IGN received a Sonic the Hedgehog 3 film mailer this week that includes a Sega Genesis cartridge that's actually playable.
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