This series of guides will teach you how to obtain the Aperture Science achievement in Portal. Before you're able to achieve this you need to have finished the game first for the Bonus Challenges to unlock.



This guide will show you how to get Gold on all of the Least Time Challenges. If you've already completed Least Time you can find my guides for Least Portals and Least Steps below.

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Test Chamber 13 is one of the easier challenges. Making sure that the cube lands on the second button correctly may take a few attempts.

• Bronze: 0:40
  
• Silver: 0:30
  
• Gold: 0:19

Test Chamber 14 is the shortest of all of the challenges. Keep an eye on where I place my Portals in the video and try to follow along.

• Bronze: 0:50
  
• Silver: 0:20
  
• Gold: 0:10

Test Chamber 15 has a bit of a learning curve to it. In the video at around 30 seconds you will notice that I'm balancing between two portals. Creep in just enough so you can see the opposite colored Portal to the one you just entered before placing another. Don't move in too far or you will end up falling out.

• Bronze: 1:45
  
• Silver: 1:25
  
• Gold: 0:54

Test Chamber 16 is my favorite. Grab a cube and use it as a shield, hold it at a downwards angle to block almost all of the fire from the turrets.

• Bronze: 1:10
  
• Silver: 1:00
  
• Gold: 0:52

Test Chamber 17 is the devil. At around 41 seconds you will notice that I place the camera slightly away from the wall instead of right up against it. Because the cube is square, if I placed the camera right up against the wall the cube would simply fall off. Balance the cube so it is mostly on the camera but at the same time giving you a lip so you can jump on top of it. This will take some practice, and I would definitely say that 17 is the hardest challenge.

• Bronze: 2:20
  
• Silver: 1:45
  
• Gold: 1:27

Test Chamber 18 really only has one tricky part. When you grab the cube after vaulting across all of the turrets, simply jump off the edge and keep moving back as you fall while holding the cube towards the turrets. This should give you just enough shield to survive and if all goes according to plan you will land on the lower level right in front of the button. This is shown in the video at around 28 seconds.

• Bronze: 2:10
  
• Silver: 2:00
  
• Gold: 1:13

If you have any questions or comments regarding this guide please feel free to leave a comment below.

You can also check out all of my other Steam Guides here.