While much of Quantum Conundrum's structure is certainly familiar if you've played Portal - you move from room to room solving environmental puzzles that require the use of a central conceit, and are fed snippets of dialogue after each successful resolution - the game's gimmick is that it allows you to manipulate elements of weight, time and gravity by flicking your mansion environment through four specific dimensions. The first one you encounter is known as the Fluffy Dimension, and here the screen gets bathed in a blue hue and all items get turned into feathery white cushions that (and this next bit is important to the puzzles, by the way) weigh very little and can be picked up and chucked for miles. Later you unlock the self-explanatory heavy dimension, and there's a genuine satisfaction to be found from the tactile oomph of the first time you shatter a glass window by flinging a pillowy safe and transforming it mid-air into a very weighty brick.

While there's some clever content to be discovered, the pace of the first 90 minutes is certainly leisurely, throwing you through what feels like an extended and largely unwanted series of expositionary devices. Eventually Quantum Conundrum comes off simmer and the puzzles do a much better job of making your brain boil, though thankfully the game - which clocks in at a good pace of about six hours if you're as stupid as me - never becomes difficult and obtuse to the point that you'll need to be looking up YouTube walkthroughs.

It's a bit of a faux pas to discuss specific solutions in a game where the pleasure is derived from figuring them out by yourself, but there's certainly some good moments to be had. I was especially fond of one puzzle about half-way through the game, and I'm trying to keep this description as obtuse as possible, where you have to fiddle with time to catch a lift on an object that you have just thrown. And the first time you solve a devilish puzzle by flipping gravity is another euphoric moment.

The shine wears off outside of the mechanical excellence of some of the puzzles, sadly. The biggest weakness is in its aesthetic, taking place across the colourfully indistinct Quadwrangle Mansion, a lifeless environment with its only real charm oozing from the fact its many repeating portraits change as you flick through the various dimensions. Your companion throughout these cartoon corridors is Professor Quadwragle, voiced by John 'Q from Star Trek' de Lancie, whose distinctive vocal chords chip in a fairly good performance even though I get the impression Airtight Games didn't have the budget for some (necessary) multiple takes.

There are some nice ideas, though: I like how you play a child, and a viewpoint close to the ground gives the mansion an interesting sense of scale. Upon death, too, the game (which, by way of another presentational failing, can't quite seem to work out if it wants to have a hidden mean streak or not) adopts a dark and occasionally amusing tone to tell you one of the things in life the child will never get to accomplish, such as firing his first housekeeper. Actually - forget the boy, I'm almost 26 and I've never even had a housekeeper let alone fired one.

Wait a second! I've managed to go five whole paragraphs without mentioning Portal, which is a happy coincidence because once you get stuck into the finer parts of Quantum Conundrum your memories of Aperture do start to dissolve away. But they will always come back. Quantum Conundrum is a fine adventure with a mechanically competent series of puzzles, and I definitely recommend it, but while the game has got plenty of brain it doesn't have nearly enough heart.

Virgin Media verdict:

• Gameplay: 8
• Graphics: 7
• Sound: 7

• Nice to play a first-person game without guns in it
• Some good puzzles
• The environment doesn't charm
• Can't shake that Portal feeling