Here is a list of the tasks you ONLY need to do to get the "Efficiency Expert" achievement. Do these steps in order. Doing these tasks fast will get you the "Speedrunner" achievement.

This guide assumes you have played the game fully at least once, as it will not tell you EVERY exact direction you need to go. You should have an idea of how to beat the levels before reading this guide.

This playthrough will take about 1 hour and 15-20 minutes.

While following this guide, you can also get these achievements during this playthrough (these are not required for the "Efficiency Expert" achievement, they are just bonuses):
"Only One Quarter" (follow this guide completely without quitting the game)
"Back in Time"
"One More Thing..."
"Navigational Instinct"
"No Gandhi points for you!"
"Student Driver"
"Flying Ace"
"Crack Shot"
"Cartographer"
"OJIDCY"
"Bomb Squad"

If you want to see a video of this route, watch https://www.youtube.com/watch?v=a00AvYG3P3k .

I should mention that trying to exploit saves will not work for the "Speedrunner" achievement. The game looks at the time when you first started and compares that with the time when you complete the game. If you fail any portion and click Continue, or load a previous save, the time will still add up.

Get your keycard, take the elevator down, use the Global Transporter to go to TSA.

DO NOT EXAMINE THE HEADS ON THE WALL.

Enter Command Center, watch videos. Do not watch the videos to the end, just click Play then Back.

When the rip occurs, enter Ready Room.

Get biochips and Journeyman Key, go down the elevator in the center.

Play normally (Flip switch, hand on scanner, cross bridge, get disc).

DO NOT EXAMINE THE HEADS ON THE WALL.

Play normally (watch new videos in Command Center, re-route robots, go back to Pegasus machine). Do not watch the videos to the end, just click Play then Back.

During this visit you just need to grab the transport pod keycard, the crowbar, and the oxygen mask. Do NOT turn towards the reactor near the oxygen mask or you will waste time viewing a movie.

BONUS ACHIEVEMENT: For the train ride, just steer LEFT once, then don't touch it (this gets you the "Student Driver" achievement).

Use the RECALL function on the Pegasus biochip once you have the oxygen mask.

BONUS ACHIEVEMENT: Doing the antidote puzzle without mistakes will get you the "OJIDCY" achivement. Look at the shapes of the molecules and select them in this order: O J I D C Y.

Get the Nitrogen Canister. DO NOT accidently transfer the emails to Sinclair's office. DO NOT get the Argon Canister or Sinclair Keycard.

Use the Crowbar to open the burned door.

KILL the robot with the electrical wires on the right of the catwalk.

Get the Stun Gun.

Fill the Nitrogen and Oxygen items. Enable the Oxygen Mask. Replace the Sleeping Gas canister.

When you are lowering the air pressure on the door, don't hold the arrow down. Instead, keep clicking it while slightly moving your mouse. It will register more inputs and allow you to move the bar faster. I usually move the mouse back and forth slightly while clicking.

When the submarine section starts, keep pressing spacebar to skip the first dialogue movie and start the submarine section faster.

LEFT LEFT RIGHT LEFT LEFT for the submarine.

Have the Retinal Biochip ready for when you get to the door before the silo minigame.

BONUS ACHIEVEMENT: If you don't screw up the silo globe minigame, you will get the "Cartographer" achievement.

Raise the door pressure to KILL the robot (Don't use the claw).

Check to see if you have the Transport Pod keycard (it's white and orange). If not, grab it.

Enter the reactor, use the filled Nitrogen and crowbar on the 2nd reactor in any direction.

Get the Card Bomb (Make a save before Mastermind in case you blow up).

BONUS ACHIEVEMENT: Solving this puzzle under 88 seconds will get you the "Back in Time" achievement.

Navigate the maze (use this to help: http://i.imgur.com/nqlhSs9.png )

Hold E before the canyon ride begins for a chance at triggering an easter egg that lets you skip the minigame and speeds up the ride to space (to save time). If you miss this easter egg, the canyon ride is RIGHT RIGHT LEFT RIGHT LEFT RIGHT.

BONUS ACHIEVEMENT: If you don't miss the turn that sends you to space, you will get the "Navigational Instinct" achievement.

Use the Graviton Cannon twice to KILL the robot.

BONUS ACHIEVEMENT: Doing this section without getting hit will get you the "Flying Ace" achievement.

BONUS ACHIEVEMENT: If you don't miss, you will get the "Crack Shot" achievement.

BONUS ACHIEVEMENT: As this point you will have triggered the requirements for the "No Gandhi points for you!" achievement. I believe this will unlock at the end of the game if not here.

Get to the roof. (DON'T accidently watch the Caldoria Heights Apartments movie in front of the Transporter when getting off of it.)

Ready your shield biochip and use card bomb on the door.

After the Sound Analysis cutscene, LEFT FORWARD RIGHT FORWARD FORWARD RIGHT, use Stun Gun

I don't really have any hints for the rooftop bomb game, just start at a node with an odd number of lines heading to it. If you are going fast, you should have about 10-15 minutes of breathing room for the speedrun achievement assuming you didn't fail anything prior.

BONUS ACHIEVEMENT: Doing the bomb section under 2 minutes will get you the "Bomb Squad" achievement.

BONUS ACHIEVEMENT: If you don't mess up the bomb game at all, you will get the "Steady Hand" achievement.

BONUS ACHIEVEMENT: After beating the game, holding E when you click Continue on the last Result screen will cause an alternative ending movie, getting you the "One More Thing..." achievement.

At this point, you should be done!