Bomber House mini-game:
Successfully complete Land mode to unlock the Bomber House mini-game played during that mode at any time..

Hard Land difficulty:
Successfully complete the game with all 100 cards in Normal Land mode.

Alternate title and ending sequence:
Purchase the token from the Info Booth in the Castle section with all 50 coins in Hard Land mode then complete the game.

Attraction mode characters:
Complete each attraction (besides the Bomber Houses) in each zone twice to get the card and medal. After completing all the attractions for a zone, the "Special" option will be unlocked in the in the Information Centers. Select that option to purchase the following characters for 10 medals.

Ao-bon (Blue Bomber): Spade Zone 
Gold Bomber: Diamond Zone 
Kuro-bon (Black Bomber): Castle 
Midori-bon (Green Bomber): Club Zone 
Pretty Bomber: Heart Zone