I'll skip the obvious comparisons to Portal since it kinda does this game a big disservice. I was somewhat intrigued by Quantum Conundrum when it was announced by Kim Swift but it wasn't until i saw the Giant Bomb QL that i was immediately sold on it.
You have 4 dimensions which can manipulate at will: Fluffy(makes things lighter), Heavy(makes things heavy as well as invincible to lasers), slow-mo and anti-gravity. In some levels you will only have access to 2 or 3 of these dimensions but where the ingeniousness of the puzzles is where you have to use multiple dimensions together to solve the puzzle. You can only be in one dimension at a time so you may have to quickly switch back and forth between them but the end result is pretty satisfying.
Another thing that made this game a instant sell for me was the addition of John de Lancie(better known as the omnipotent "Q" from the Star Trek franchise) playing the role of Professor Fitz Quadrangle(your Uncle in the game).
The story has an interesting twist at the end and it leaves me wondering how future DLC with fit into the game but it's definitely a fun ride from beginning to end. If you like puzzle games with a lot of trial and error then you should buy this game!