Kirby 64: The Crystal Shards Codes -

Control title screen:
Hold + + at the title screen and Kirby will say "Hiiiii".

Sound test:
Successfully complete the game to unlock a sound test selection on the options screen.

Bonus modes:
Collect all crystals in the game until the status on the saved game selection screen is at 100%. Options for Boss battles and a intermission scene display will be unlocked.

Evil Kirby:
Collect all enemy cards, all crystals, then win the Boss battle.

Extra lives:
To get an extra life, get the star at the beginning. Press and select "Try Again". Go to the same level and go back to get the star again. Repeat this as many times as needed.

Higher mini-games difficulty settings:
Successfully complete the mini-games under the easy difficulty setting to unlock the normal setting. Complete the mini-games under the normal setting to unlock the hard setting. Complete the mini-games under the hard setting to unlock the intense setting.

Moves (combos) and ratings:

Fire + Stone: Rock shooter (average)a
Fire + Ice: Ice and fire blower (bad)
Fire + Needle: Bow and arrow with fire arrow (fair)m
Fire + Bomb: Fireworks (average)a
Fire + Spark: Solar powered fire (fair)
Fire + Cutter: Fire sword (good)
Fire + Fire: Fire bird (good)
Fire: Fire ball (fair)l
Stone + Ice: Skating soap (bad)
Stone + Needle: Drill (good)
Stone + Bomb: Dynamite (very good)
Stone + Spark: Electric rope tied to stone (very good)
Stone + Cutter: Stone cutter (bad)
Stone + Stone: Big rock (very good)
Stone: Rock (fair)
Ice + Needle: Snow flake (bad)
Ice + Bomb: Snowman bomb (average)
Ice + Spark: Refrigerator (food gives you health) (very good)
Ice + Cutter: Skate (good)
Ice + Ice: Snowball (fair)
Ice: Ice blower (good)
Needle + Bomb: Spikey bomb (very good)
Needle + Spark: Thunderbolt (average)
Needle + Cutter: Bite (commercial) (fair)
Needle + Needle: Spikey gadgets (good)
Needle: Spike ball (bad)o
Bomb + Spark: Light bulb (bad)o
Bomb + Cutter: Bomb that hooks onto opponent (good)
Bomb + Bomb: Missile launcher (very good)
Bomb: Bomb (average)
Spark + Cutter: Electrical double bladed sword (best)
Spark + Spark: Electric ball (good)
Spark: Electric shock (average)
Cutter + Cutter: Boomerang with blades (good)
Cutter: Boomerang (bad)

Break through walls:
There are various walls that must be broken by specific abilities. The ability depends on the color of the wall.

Red: Fire
Blue: Ice
Green: Cutter
Orange: Spike
Yellow: Electric
Black: Bomb
Brown: Stone
Red + Blue: Melting icecube
Red + Green: Fire sword
Red + Orange: Fire arrow
Red + Yellow: Sparking exploder
Red + Black: Fireworks
Red + Brown: Volcano