Quantum Conflabbit
When I say that Quantum Conundrum lacks personality, that isn't to mean that it has none. As before: there are some distinct signs of life in the setting and theme, but it really, just, isn't that much. The Professor's bad jokes, and the samey architecture of the manor, do little to offset the tedium of the game's puzzles. And, really, that's the core problem with Quantum Conundrum -- the puzzles become tedious.
Portal, and even its lengthier sequel, excelled at the "skirt" principle of level design: long enough to cover the subject, short enough to keep things interesting. But Quantum Conundrum tends to simply be too long for its own good. Puzzles too-often have you repeating tasks you've already done in previous solutions; not to combine them with new ideas in inventive ways, but simply to pass time. Entire puzzles can feel like filler. And the manor has, uh... around 50 discrete puzzle stages, some of which include more than one room.
It's not often I can critize a game for having too many levels, but that's definitely the feeling here: the dimension-shifting puzzle mechanics are simply spread too thin over this length of game. And as a result, the moment-to-moment gameplay doesn't change rapidly enough to keep things interesting.
Better than: Mario vs. Donkey Kong: Mini-Land Mayhem!
Not as good as: Portal 2, Q.U.B.E.
One cool design note: portraits on the manor's walls will change based on the dimension, e.g. a portrait of an old lady, when time is slowed, shows the shadow of Death standing behind her. That's a genuinely awesome touch.
Progress: Gave up -- midway through the Yellow Wing.