Status: Main game complete, unlikely to do more
Most intriguing idea: A physics game that depends on actually altering physical properties.
Best design decision: The reversed-gravity dimension
Worst design decision: Precision platforming.
The laziest thing possible would be to say that Quantum Conundrum is a Portal clone, but Quantum Conundrum is, lazily enough, a Portal clone. It’s a first-person game ✓ where you use a special invention ✓ to solve physics puzzles ✓ with finicky platforming ✓ to the accompaniment of a disembodied helpful/antagonistic voice ✓ that talks about science a lot ✓. The precise nature of the physics manipulation differs, of course: Quantum Conundrum allows the player to change the mass and durability of objects, slow down time, and invert gravity. In certain spots the problem-solving is actually quite inspired, but in too many cases an over-reliance on precision platforming makes solutions too much harder to implement than they are to devise.
Quantum Conundrum also noticeably fails at creating a compelling environment or characters. The mansion is sparse and repetitive, failing to look like anything more than a series of test chambers with unusually lavish furnishings. The mad-scientist uncle character whose voice follows you around the place comes across as purely being an ass. While his dialogue isn’t that different in character from GLaDOS’, it grates a lot more because he’s delivering those insults to a (presumably frightened) child who’s trying to save his life. Especially in light of the absurdly abrupt ending, Quantum Conundrum just doesn’t offer a compelling enough world to justify the frustration of working through its puzzles.
If you can’t say anything nice… When Quantum Conundrum de-emphasizes the platforming, it produces some startlingly clever and rewarding puzzles.