From WiKirby, your independent source of Kirby knowledge.
Bomb-Spark is a Power Combo in Kirby 64: The Crystal Shards that combines the Bomb and Spark abilities. It allows Kirby to transform into a light bulb surrounded by sparks, which will hit enemies, as long as the player holds the B button. After a few moments the light bulb explodes in many shards, which will also hit nearby enemies. It can also be used to light up dark spaces, like in one room on Stage 4 of Rock Star, where the light bulb is needed to obtain hints to get a Crystal Shard.
While in his light bulb form Kirby is unable to crouch, hover, or dash. Kirby can harm enemies by walking into them, but he will still take damage from their projectiles.
Like the other abilities in Kirby 64: The Crystal Shards, this ability does not change Kirby's physical appearance until it is used.