Instructions
Sketch Strategy
Destroy the two generators in the front of the room. If you freed enough gremlins during the game, they destroy these generators for you. If you did not, wait for the generator door to open, then spray the red button inside with thinner to destroy it.
Use the D-Pad to select a TV sketch. Aim the pointer at the pressure pad on the left side of the attic. Press the "-" button to drop the TV sketch on the pad.
Select and use a Watch sketch to slow down time. Run to the stacked boxes in the center of the attack. Climb the boxes to see another pad.
Select an Anchor sketch. Drop the Anchor sketch on the pad. Jump down and follow the trolley track. When you reach the end of the track, jump to the other side.
Step on the pad on the other side of the track. If you reached the pad in time, a piece of the track falls from the ceiling. With the track completed, a trolley car races down the track and smashes into the last generator, destroying it. You defeat the Mad Doctor when this happens.
Thinner Strategy
Approach one of the two generators in the front of the attic. Any gremlins you helped earlier will destroy these generators, so you do not have to. If you ignored the gremlins, you need to destroy them alone.
Run up to the Beetleworx enemy that the generator spits out. Shake the Wii Remote to attack it. When it flips on its back, blast it with thinner to blow it up. With the Beetleworx destroyed, the generator opens its door to release another.
Stand in front of the generator door as it opens. Press the D-Pad left or right to choose a Watch Sketch. Tap "-" to use it. You now have more time to attack the generator.
Spray thinner at the red button inside the generator. If you do so quickly enough, it blows up. Run to the generator on the other side of the room and repeat the process.
Go to the generator near the Mad Doctor and blow it up as you did the others. When you do this, you win the battle.