Unlock the following modes by performing the corresponding tasks:
MODE - HOW TO UNLOCK Boss Battle mode - Beat Boss Survival mode. Boss Survival mode - Beat the game with both characters. Maniac mode - Beat the game on Expert difficulty. Expert mode - Beat the game on Standard difficulty to unlock Expert difficulty.
After Master Albert shows his true intentions, you will be presented with four missions. Complete the Highway, The Scrapyard, and The Control Center, skip the fourth and return to Hunter's Camp. Go all the way to the basketball goal and open the way to the Quarry, then complete the mission and you will end up at the entrance of the Quarry. You cannot transform back to Model A or any transformation until you take the fourth mission you skipped. The transformation is accessible during the mission. Complete the mission and the area you completed will open. However, the events that occurred in the Quarry will be gone and you cannot progress in the game.