Transforming into a lightbulb is a bright idea since it will allow you to harm enemies by simply walking into them.  ” — Description • Nintendo Power (Volume #134) Light Bulb is a Power Combo used in  made by a combination of Kirby 64: The Crystal Shards Spark and Bomb abilities. The light bulb illuminates dark areas, and is needed to view answers given to Kirby by Adeleine in Pix's ship on Rock Star, so that he may obtain the next Crystal Shard.
With the Light Bulb ability, Kirby can walk around and jump as he normally could (but he cannot fly), and he can destroy enemies that come on contact with him or the debris from his explosion. It is very similar to the
Explosive Snowman ability.
Kirby becomes a light bulb on legs and can walk freely. This works like the
Light ability, until Kirby explodes, damaging all near.
Kirby turns into a walking light bulb that can explode. ” — Description • Official Strategy guide
Kirby becomes a small light bulb, burning brightly. Eventually, he burns too brightly and explodes, destroying nearby enemies. ” — Description • Official Strategy guide