Spiked balls are sitting on top of exploding barrels with fire next to them. This is a tricky level that destroys the starite quite easily if you are not careful.
To pass the level, place an invincible immovable object on top of the starlite and below the steel balls to prevent it from getting hurt. Drop an object to ignite the barrel at the very top. The spiked ball will fall and destroy the fire and barrels.
Equip Maxwell with a flying device. Carefully descend to the bottom levels. Carefully remove the invincible immovable object. Retrieve the starlite.
Consider going through the left of the stage with digging tools can make this stage a bit easier.
Round 1:
Invincible immovable object: Invincible immovable platform
Drop an object: Rock
Flying device: Talaria
Digging Too: Shovel
Round 2:
Invincible immovable object: Invincible immovable table
Drop an object: Stone
Flying device: Wings
Digging Too: Spade
Round 3:
Invincible immovable object: Line up with 3 x Invincible immovable Pebble
Drop an object: Steel Ball
Flying device: Flying Shoe
Digging Too: Pick
Scribblenauts Remix 15-6 Cheats Hints gallery:
15-6-1-a: Prevent the spiked balls from falling!
15-6-1-b: Put the fires out.
15-6-1-c: The easiest path is down and to the left.