Hot Stuff is the eighth level in Underwonderworld. The first part of the level involves Stinky and Loof making a bridge out of Steel Boxes in the lava while dodging a Kaboom!, and the second part has the duo using a Steel Box from the first part to trap a Kaboom! so that all the Rainbow Coins can be collected.
If need be, switch to Loof for ease of movement. Locate the steel box (orange "X") blocking the passage to the upper room, and push it one tile left.
Keeping clear of the Kaboom, move the steel box in the lower-right corner to align with the wall (five tiles above its initial position).
Stand aside and wait for the Kaboom to pass. Once it enters the dead-end, push the metal box up to trap and destroy it at the orange "X".
Position Loof at the green "X", and send Stinky into the upper room. Push the steel boxes along the yellow and brown arrows, then collect the bonus coins.
Get Stinky to progressively retrieve six steel boxes from the room and place them just below the green "X", then let Loof dump them into the lava along the green arrow (but make sure to not step onto the conveyor belt yourself).
Get a seventh box from the room and place it on the black "X".
Now move Stinky to the cyan "X", then get Loof to push the seventh box to Stinky's side.
Switch to Stinky, push the box onto the conveyor and follow through. Upon landing, go to the white "X".
Switch to Loof, push the seventh box down beside Stinky, then move to a safe spot (e.g. the collapsible bridge) to hide from the Kaboom.
Lastly, get Stinky to push the box and trap the Kaboom at the purple "X" (be sure to retain the Rainbow coins there first). Once the Kaboom is destroyed, collect the remaining coins.
Use the last two steel boxes to bridge the lava tile beside the right-hand wall and exit the level.
