Roboiler

The Robo-Boiler, also referred to as Roboboiler, is the second boss appeared in Sonic the Hedgehog Spinball. This bizarre chamber is featured at the highest room of Lava Powerhouse.

The red and hot Robo-Boiler room contains four yellow Roboheads, each resembling Doctor Robotnik, the creator of the chamber. Above corners of the chamber are two active steam jet machines located. In the 8-bit version of the game, the Robo-Boiler only has two robotic heads.

Overview
Each head moves to one of five locations in the boiler, and they seem to vomit lava whenever Sonic hits them. The player has to destroy all four of the robotic faces by jumping into their chamber and rattling about; but whenever one gets taken out after five hits, the remaining heads will temporarily vanish, leaving Sonic to tumble out of the vessel and have to make his way back up. In 8-bit version of the game, one of two robotic heads don't vanish after destroying another one and the player is able to destroy the second one at the same time. After destroying all robotic heads, the player destroys the chamber and clears the stage.

The most notable hazards in the Robo-Boiler room, are the steam jets guarding the above corners of the chamber. When ever the player times his/her Spin Jump wrong, the hatch below the player opens and throws him down. There are two targets on the bottom of the tank - hitting these will cause the drain plugs in the level to close.

In this instance, draining the ball down either the left or right hand side will cause Sonic to fall down into the upper steam arena. Should the player drain the ball down the center however (or the sides if the drain plugs are still open) will have Sonic tumbling down to the bottom of the level where he will emerge from a hole above a cauldron of boiling hot lava. To rescue himself, Sonic needs to get enough of a swing on the chain hanging from the hole and let go at the right moment. However the chain is weak and will break if Sonic stays on it for too long as the game gives you a countdown from five. This can be done twice - a third center drain will spell certain death for Sonic.

Trivia

 * Unlike the other rooms in the level, the drain plugs in the boss room do not open again after they have and will stay closed.