Head up and to the right until your path is blocked by some rocks. Lift several of these and drop them to the left to clear a path for yourself (or you can just build up speed and bash through), then continue right. Head up and push the lever to the left or right, then go through the open gate. Follow the passage through a green force field, then you will reach another gate controlled by a button; pick up a rock from the left and drop it on the button, then head on through. Further to the right, lift up the cover on the pipe, then follow it down to a new area.
Go over to the left and pull up the piston to fire a small metal ball to the right; it disappears into another pipe. Go further left and lift the small rocks out of the small passage down. Use one of these to block the exit pipe for the metal ball, then lift the piston again. Pick up the metal ball and drop it down on to the button to the left. Go through the gate and down through another force field.
Pull the piston between the 4 colored lights to start a memory game section. Repeat the correct pattern of 3 lights, 4 lights and 5 lights and the next gate will open. Pull the piston in the next area and a light sphere will appear. Push this to the right until you find another pipe cover to open. Push the sphere down inside this pipe. Continue right through a green force field, then head a long way down before going left. You will find 4 red buttons here; pressing each button activates a light and opens a gate. You need to press 3 of these buttons down, as one light is already on. Go right and pick up the small square blocks, placing them on the correct buttons - they are not heavy enough to hold the buttons down. Go right again and pick up a metal bar, dropping it across the blocks to weigh them all down. The gate should now open. Grab your light sphere and head left.
The next room has 3 pistons, each of which rotates large pieces of metal differing amounts. You must get the metal to line up with the hole in the background. The easiest method is just to pull the middle piston twice, but there are many other simple solutions. Once you are done, pick up the light sphere and continue left. Drop the sphere down the open pipe, then head through the left one to exit this section.
Pick up your light sphere and follow a long tunnel to the left and down, eventually opening up to a large orange cavern. Deposit the light sphere in the claw of the pacemaker, then head right through the open gate. The first puzzle has 3 sets of scales and a variety of different blocks. You need to balance the weights in the scales so that the sliding openings above all line up enough for you to fly through. Once done, continue up, through a force field and around to the right.
Head along a corridor with gears in the background and at the end will be a closed gate with a broken lever. Pick up the rock here and drop it back in a turning gear to the left; this will explode, then will roll down and smash the gate. Go through to the right and down. Use your tractor beam on the red sphere until you hear the next gate lock open, then head through to the left.
In the next area you will find 4 mirrors that can be rotated. You need to reflect the laser beam to hit the sensor on the left. Just rotate the bottom left mirror and the top right mirror correctly to achieve this. Head through the gate to the left, then up to return to the pacemaker.
Now you can go through the open gate to the bottom left. Follow this passage through a pipe and you will come to another larger chamber. There is a closed gate at the bottom right, with a broken cable over some water. Drop everything you can find into the water to raise the level enough so the current will pass through the cables (this will include a couple of rocks from the left, and some other objects from a small room to the top left). The gate will eventually open so you can go through.
Head right and you will find another laser that needs to be directed to a sensor at the top right. Direct it down, then to the far right, then pick up the third mirror and hover near the top right to reflect the laser at the sensor long enough for the gate to open.
Next comes the hardest puzzle so far. Go back to the left where the laser was pointing downwards to start. Place one of the square metal blocks here and one of the mirrors on top of this; the laser will be deflected far to the right now. Go far right to where you angled 4 mirrors previously, and make sure the bottom two are horizontal. Now both beams should pass over the water between the two areas. Bring one of the mobile mirrors from the left here and drop it in the water so it reflects one beam up and one beam down. The light sphere should soon be released. Carry it back up to the pacemaker area and deposit it in a second claw here. Now you can head through a new open gate to the left. Pull the piston up, and enter the tube to the left.
Fly to the left and down slightly. Pull up a piston on the left and a bomb will drop down to the right. Pick this up and hold it next to a red blob near a closed gate; when it explodes the gate will open. Head right and you will find another large area. There is a furnace to the right with a temperature gauge next to it. You need to pick up 4 lumps of coal and drop them in the furnace, but you need to free them each from the ground with a bomb first. Collect a bomb by pulling the piston on the left, then drop it near a piece of coal, pick up the coal and drop it in the furnace. Repeat this with the 4 lumps of coal in this cavern.
Head down and left through a force field to an area with a lever. Moving the lever adjusts the positions of two metal barriers that block passage through a pipe below. Pick up the metal bar from the ground just to the right and wedge it in the gears above to stop them turning. Now you can open the pipe cover here. Move the lever to the right, then take the metal bar down into the top pipe and drop it across where the first metal barrier comes down. Now move the lever to the left, and you should be able to fly down into the lower pipe and all the way around to the next area to the left.
Go up through another force field and pick up the large metal bar here so it is vertical. Fly up and drop it on a big button on the left. A small gate to the top right will slowly open so you can head through. In the next area, make a bomb and drop it between the bottom left red organs. Very quickly make another an explode it between the top right organs. Very quickly again make another bomb and explode it over the final organ, then quickly dash through the gate before it closes. Pull the piston on the other side and the gate will then stay open.
Go down and pick up the rock at the bottom. Take it back to the left where you dropped the metal bar before, and drop the rock on the button instead. Take the bar to the far right where you found the rock, and move it through the gate to push the lever to the right. Now fly through the gate just above. There are two more lumps of coal in this area. Open the next gate with the piston, then use bombs to free the coal and drop these last two pieces in the furnace to the right to fill the gauge to the top.
Now if you go to the bottom left of this area you will see a machine with water and fire symbols on the side. Pick up the small jar to the right and use it to collect some water from here. Drop the jar into the machine. Next fly up and collect one of the fiery rocks and drop it in the machine. Repeat this a second time with the water and the fire, and the water level to the right will have dropped so you can fly through.
Pull up a piston and go forward through a force field. Continue right and use the piston to free another light sphere. Take it with you, pushing the lever to the right. In the next room, push the sphere into the tube on the right. Take the bright sphere back to the left and deposit it in the claw. After a short delay, the gate above will open, so head through.
In the next room fly past the piston and pick up the suitcase floating in the water. Take it back to the left and drop it in the orange glowing receptacle. Now pull the piston and a swimming suit will be applied to you. Swim through a long underwater tunnel to reach the next puzzle. Here you should activate the sensor to make the ball go up and deactivate it so it falls; navigate the light sphere from right to left to open the gate so you can continue. Repeat this process in the next room.
Go left and down and pick up the light sphere, then push it through the pipe at the top. Go down through the force field and pull the piston. Go through the gate and all the way back up to the start of this section. Pull the piston here, then go through the pipe to the right.
Carry the light sphere back to the pacemaker on the right and insert it into the 3rd claw. Now go through the gate to the lower left and follow this around and down to the small pool of water just right of a lever. Head down through the water here and pick up a stone from the lowest point, then continue right and then far down. Following the bottom of the water, you will find a large button that you can weigh down with the rock. Go through the pipe that opens to the right and you will reach a new area.
Pull the piston to make a bomb. Pick it up and quickly go around to the right, stopping behind the barrier so the laser does not blow up the bomb. Quickly keep going up and use the bomb to explode the red organ. Now you can head through the open gate here.
In the next area, make a bomb and drop it into the pipe down to the left. Quickly fly left and block the vertical laser so the bomb can fly past, then immediately go up and block the next laser. After the bomb explodes next to the organ, fly immediately left through the gate before it closes.
Follow this passage until you reach a large colorful display. You need to change the colors so that no two adjacent segments have the same color. Once you have done this, head right through the gate. Use the piston to release the light sphere, then push it into the pipe on the right and follow it through. Drag the sphere to the last claw on the pacemaker.
Now you have to move the small lights around so they cast light on the five generators around the outside of this chamber. Use the smallest light at the top left, the medium light near the top right and the largest light at the bottom. Once all 5 generators are powered, a massive gate will open at the top right. Go through here, pull the piston and head through the pipe.
Head right and slightly up, and fly through the long tunnel to find another memory game. Pull the left piston and watch the speakers make sounds - it is important whether the upper, lower or both speakers are vibrating with each beat. Now recreate the sound by using the buttons in the top and bottom rows on the right. Once you have the pattern correct, pull the right piston. If you get it wrong you can try again. If you get it right, you must repeat the process but with 8 beats instead of just 4. When you get this one correct, a gate on the right will open. Go through and pull the piston, then take the light sphere over to the left and deposit it just left of your pipe. Go back through the pipe and find the light sphere at the other end.
Deposit the sphere in the claw below. Pull the two pistons on the right side to light their globes, but leave the left globe unlit, then continue down further. Push the lever to the right and the power will travel down further. Make sure you turn off both globes above, and continue down to find 4 more. Turn all of these 4 globes on, then continue further down.
Continue right past some TV screens, and another robot will close a gate before you can get through. Pull the piston here, and take note of the symbols along the top row of each of the TV screens. Go left and pick up a box with one of the symbols and drop it beneath the corresponding TV. Repeat this with 4 more boxes, then pull the piston and continue right.
Go up and then a long way to the right, where you will eventually reach a lever. Push it, but the gate will only partially open. You can go through the floor just to the left of here, and follow this tunnel down a long way. When you reach 3 red balls and some powerful fans, just ignore the balls and fly straight to the lower right over the moving staircase. Keep going right, where you will find a very heavy box on the ground. Lift it by its corner and tip it to the right, then continue doing this to move it to the right into an elevator. Go up in the elevator, and exit through a small pipe on the right.
Go right to find a large container with objects falling into it. Fly beneath this and over to its right side, then lift the small red cover so you can push the button here. Fly to the right through a small panel that has just opened, and pull the piston inside here. Go back out and push the button again, then go through the new small panel that has just opened above the first. Go right and slightly down and pull the piston, then go through the large tube below, heading to the far right.
In a room with a very large wheel, go to the top right and push the lever, but it won't work properly. Go through a small hidden opening at the bottom right leading into a pipe to reach a control area. Pull out the 3 plugs here and you will be sucked into one of the exhaust pipes. When you regain control, fly straight up and wait near the covered pipe; when the cover opens fly in and follow this pipe to its other end.
Pull the piston here and a camera will drop down to inspect the plate, then leave again. Go down and then left until you find a battery in a small container on the left wall. Take the battery to the far right, through a gate, then down and to the left. You will reach the gate that wouldn't open before, but from the other side. Lift up and discard 4 floor panels here so you can pull out the old battery and insert your new one, and the gate will open.
There are two possible endings based on what you do from here. You can select either of them and then select to Continue your game from the main menu afterwards, and you will be returned to this spot so you can select the other option.
Head left to the large room and then down to the right through the hidden pipe entrance. Follow this to the room where you unplugged things earlier. Pick up the broken robot here and carry it back through the pipes, up through the broken gate that you fixed, then to the right, up and to the left to a glowing orange cauldron. Drop the robot inside and the cauldron will change to green. Pull the piston just to the right.
Head left to the large room and then down to the right through the hidden pipe entrance. Follow this to the room where you unplugged things earlier. Pick up the broken robot here and carry it back through the pipes, up through the broken gate that you fixed, then to the right, up and up further. Drop the robot on the plate you found earlier and pull the piston so the camera comes out and scans the robot. Go up through the gate that opens, then press the button and continue up through the pipe. Follow the opening all the way out to the surface.