Walkthrough (part 1):
-Look to your left. Shoot an orange portal on the angled panel. Then, look to your right. You should see a cube and an excursion funnel. Shoot a blue portal past the laser field, where the funnel is pointing.
-Leave the cube in the funnel and quickly proceed to the button that turns on a fizzler. What you want to do is FIZZLE the cube so that it SLIGHTLY RISES and blocks the laser.
-This will turn on a circuit that will lower some glass panels. Shoot a blue portal behind them and an orange portal someplace reachable.
-Do what GLaDOS says, that is, go ahead and grab another one. Take it through the portal to the button. It turns off a fizzler.

Walkthrough (part 2):
-As you exit the small room through the fizzler, you should see a column of white walls in front of yourself. Shoot a blue portal between the first and second block of this column and an orange portal at the excursion funnel. Jump into the extended funnel.
-Quickly place gradually higher blue portals until you reach the room with the propulsion gel.
-If you placed the first portal on the very bottom instead of between the 1st and 2nd block, the cube would get caught in the funnel and float off the button.
-Shoot an orange portal at the propulsion gel.
-Jump down to the main room and look at the ceiling. You should see a strip of white tiles. Shoot blue portals on different places until you painted a propulsion gel runway.
-Go through the fizzler to the cube and emancipate it to get a new one.

Walkthrough (part 3)
-Go with the cube to the runway. Instead of looking in front of yourself, however, look at the ceiling. This way you will allow the cube to bypass the large fizzler.
-If you did as you were told, there's no reason for anything to go wrong, but if the cube somehow got fizzled, dive into the goo.
-Otherwise, place the cube on the button.
-Proceed to the final Chamberlock.
-Congratulations! You completed Thinking with More than Portals's basic campaign!