I'm not going to waste your time. This game is great and if you have a few spare hours, I have a hard time thinking you would call playing this game a waste.
The first thing I will touch on is the gameplay. You have two commands: jump and grab. But the control scheme is just a way for you to focus on the mechanics. We're looking at physics-based puzzle solving here. Usually the first game that comes to mind when I say "physics-based puzzle solving" is Half-Life 2. Unlike that game, this is 2D and has very little combat. You will more than likely feel cheated by the trial-and-error nature of a few parts, but the game loads so fast and so close to where you died that I don't think this is an issue. There is also a nice progression in the world of Limbo that complements the change of pace in the game. From a gameplay perspective, this is solid stuff.
Atmosphere is a big component of the game and will ultimately, I think, be what makes you dig it or turn away from it. The whole game is minimalist black and white. The music is creepy and understated, but I also feel it is soothing in a weird way and gave me a sensation to keep moving forward. I would say that it inspires you to keep moving forward because it never really gives you a clear-cut break in the experience to quit the game. Or, at least, that's what happened to me.
So, here's my little anecdote about Limbo. A roommate of mine had his girlfriend come over to our house because they were going out that night. I was playing the game in the living room and she noticed it. We said our hellos and she asked what I was playing. I let her know the supposed premise of the game (That one is still ambiguous enough to cause debate.) and she was intrigued. Before either one of us had really noticed, I had completed the game. It was the first time I had inadvertently played a game for someone else's amusement. Limbo hadn't just sucked me in; it had sucked in the people around me who had just noticed the game.
I have completed the game dozens of times (Don't worry, that's not bragging because it's not hard to do.) and have gotten all the achievements (Okay, that one is a brag, because there's an achievement for not dying five or more times. ;)) I feel like I had taken something away from it that I could call my own. I have a familiarity with it that makes it feel like an old friend. It's this kind of, for lack of a better term, intimate experience with a game that makes me keep playing. There are games that I will play, never beat and just discard because why bother? If I don't like a game, I'm not going to waste my time with it anymore. If you can beat a game so many times and still feel like it has life and you decide to just, on a whim, complete it again, that says something significant to me. And I've come to find I am a very jaded gamer over the last decade.