Part 8: Continue through the now deactivated laser barrier in the center to the Bridge until the cutscene with Gateau and Napoleon starts. - The bridge is blown up.
Talk to Napoleon. He'll throw you across the gap in the bridge.
Continue to the Outside and climb to the top floor to enter Part 9.
As soon as you enter the Tetron Room the first part of the final battle against Gateau starts.
After you defeated him, enter the machine and eventually face Gateau for the last
When he's done, the end credits start.
At this point the game cannot be resumed. You'll have to answer Napoleon's second question “Are you ready?” with “No” to continue exploring the worlds of Robotrek.