Obligatory Portal comparison: you're solving science puzzles with a snarky voice over an intercom guiding you.
With that out of the way, Quantum Conundrum is a game that stands well on its own merits. The gameplay, based around creatively shifting between multiple dimensions with different effects, is simple enough that few puzzles have a solution where you'll say 'I didn't know I could do THAT', while still managing to provide a fairly steady level of critical thinking. There's not too much handholding—your uncle chimes in on occasion, but you can't rely on him to be much help at all. As opposed to a wholly cerebral approach, there's also a good amount of platforming, giving the game a good sense of motion as well. You'll gradually build up a small arsenal of tricks at your disposal, from the simple mid-air heavyify glass-smasher to the more complicated slow-mo fling mount leading into an alternating gravity float across a chasm.
The graphics look great, with the cartoony style working well and with very few visual glitches at all to speak of. Those with less powerful computers might wish to wait a bit—there are options supposedly toggleable in the UE3 config files for the game, but as it is (reviewing this soon after launch) there's no way to turn down some of the more advanced effects like the motion blur and ambient occlusion. The dimensions, especially the Fluffy and Heavy dimensions, look iconic in their own way and seeing the same room in multiple different themes is pretty interesting to look at. The music is good and fits into the background neatly as boppy science tunes of various moods.
The writing isn't going to make you stop and laugh and sadly there's not a lot of eminently quotable lines, but it still works well as a goofy, Dexter's Lab-ish science romp with lots of one-off jokes and references. There are complaints rolling around about a somewhat abrupt ending—the final 'puzzle' is a fairly simple one (after a couple of particularly complex ones) but in my opinion, it didn't feel out of nowhere or like I was cheated out of game time. Having two sets of DLC with achievements already planned out on release is not something I'm a proponent of, mind you, but I didn't feel as if I was cheated out of an ending.
So is it another that-game
? No. But is it fun and worth the price? Definitely.