Talented young games designer Kim Swift had “huge success” with her debut masterpiece Portal. It was a triumph.
Swift's first game since leaving Valve is a similar three-dimensional puzzler blending humour with brainteasers. Quantum Conundrum, available now on Xbox Live Arcade, PlayStation Network and Steam, is good fun and value for money but lacks Portal’s polish.
You play a youngster trapped in his eccentric uncle’s mansion, armed with a fascinating invention called the Interdimensional Shift Device (which resembles a Nintendo Power Glove from the 1980s).
The four different dimensions you can shift between are "fluffy" where everything is much lighter than normal, another where objects are much heavier, one where time is slowed and another where gravity is reversed.
As something of a mad scientist, your uncle has fitted out his house with a series of puzzle rooms to experiment with his inventions. It's a set-up that will be very familiar to Portal players, and facilitates the same mix of platform leaping and puzzle solving.
Players switch between dimensions to enable them to carry and throw previously heavy items, before switching back to heavy mode to smash glass or trigger switches, or to slow motion to use items as stepping stones.
Giant fans, lasers, springboards and other contrivances help ensure variety, even if they don’t make much sense.
There are some ingenious ideas introduced after a relatively dull opening, and the game soon seriously tests your dexterity as well as your noggin.
Tougher challenges require perfect timing and precision jumping, and will try a player’s patience.
Working out the solution isn't usually difficult, but pulling off the joypad gymnastics demanded can be a trial.
Perhaps the biggest conundrum in the game is why there is such emphasis on platform leaping when it is widely recognised that the first-person perspective simply can't offer the precision necessary.
You might also scratch your head at why the uncle so often chastises his young nephew despite desperately needing his help.
It's a game that entertains as well as challenges, but one that is far from the essential purchase that Portal represented.
What have you been playing lately?
Jason Hill is on Twitter: @thatjason