Portal 2: Top 10 Test Chambers

We've picked out the ten chambers we found most challenging, memorable and just plain great during our single-player playthrough. And, for those of you yet to beat the game in its entirety or keen to relive the moment from another's perspective, we've also captured the solution to each.

In short, these are the puzzles that left us bewildered, frustrated and awe-struck in equal measure - and filled with admiration for Valve's fiendish ingenuity. This, of course, only represents our experience. We'd love to know how it was for you, so please let us know your standout, synapse-busting moments below. Meanwhile, here, in reverse order of misery/joy is our top ten.

And, if you haven't played Portal 2 yet then, y'know, spoilers.

4) Chapter 7-2

Portal 2 is at its best when it delivers huge tests, set across - at first sight - numerous unconnected sections. The scale of it is overwhelming, leading to the daunting question: 'How exactly do I get over there?.'

And no sooner have you figured out the necessary Propulsion/Repulsion combo than you're presented with an entirely new perspective on the puzzle - and you realise you've got to be even smarter to make the final long leap to the exit.

3) Chapter 8-8

Oh, Valve, you cunning buggers. In a title not exactly short on great moments, the sheer craft and intricacy of this chamber stands out. So much is crammed into the (relatively) confined space, played on by the developer in Wheatley's instruction to solve it "ten times faster" than normal. Good luck with that.

And when the chamber is finally bested, Wheatley delivers the delicious line: "Why are you making it so hard for me?!"

2) Chapter 8-11

The final test, and by now you have been conditioned to realise that nothing is ever as straightforward as it seems in the world of Portal. The set-up may appear tantalisingly routine, but you know better than that.

Success here is measured by how long it takes to turn your mind inside-out until it stumbles upon a game-changer: reverse the flow of paint! We can confirm that this took us so long to figure out that we literally punched the air with joy when it was finally completed.

1) Chapter 7-5

Portal 2's greatest test is also its largest and most dramatic. Dizzying in scale and substance, this chamber (somehow that word doesn't do it justice) tasks the player with scaling a massive structure via great leaps and thrilling free falls.

All three gels must be utilised in concert to reach the top, only to then discover that you must climb higher and higher in a shower of Conversion Gel before emerging into a second huge area and finally ascending through a giant hatch in the sky. Magnificent.