Boss battle:
Defeat the last Boss to enable the "B" selection on the options screen. Choose this option to begin a battle with all six Bosses in order, with one life, and no chance to heal.

Graphics test:
Complete 100% of the game to enable the "?" selection on the options screen. Choose this option to view all the introduction to the game and all worlds and the various endings.

Regain health:
Summon your assistant, then assimilate him again to regain a small amount of energy.

Hint: Fun Bones level:
After completing lands 1 to 4, go opening menu and select the game that you have reached land 5. Select "Options" and then select the "M" instead of the sound check (the small music note). This will take you to a little game center where you can play each Bones game in order.

Powers:

Character	Ice	Fire	Stone	Electric	Cutter	Needle	Parasol	Broom
Kirby	Ice Blow	Fireball	Stone Drop	Zap!	Cutter Boomerang	Spikeball	Parasol Thwack	Broom Sweep
Owl	Ice Wing	Fire Drop	Stone Drop	Lightning	Feather Cutter	Needle Drop	Parasol Tornado	Feather Duster
Bird	Ice Winder	Fire Bird	Stone Jump	Remote Control Bird	Bird Kite	Flying Peck	Bouncy Bird	Water Balloon
Pinky	Snowball Throw	Hot Air Balloon	Stone Spin	Laser	Pinky Sweep	Five Way Needle	Parasol Ride	Magic Broom
Cat	Ice Jet	Fire Wall	Stone Pound	Static Electric	Beam Cutter	Needle Gun	Parasol Pogo	Magic Carpet
Hamster	Snowman	Flamer	Stone Roller	Electric Wave	Kirby Boomerang	Back Spikes	Parasol Kirby	Brusher
Fish	Ice Block	Fire Bolt	Stone Drop	Light Bulb	Cutter Bolt	Spikeball	Parasol Mouth	Plunger