I just finished the game earlier today (early review code), with the game clocking me at about 2 hours 10 minutes of playtime (though I think it's actually a little more than that. I think it's tracking the recorded time it takes you to get through a level, for leaderboard purposes, which means the clock resets when you die at checkpoints). I went back to get the collectables I missed, which wasn't many, and thankfully it's quick and easy to find out where you're missing stuff and jump right to that area. An hour at most of extra work later and I'm 100% done.
So since I know there are people for whom easy achievements and short length will either sell you on the game or make you spend your money elsewhere, I thought I'd let you know. I enjoyed it enough, personally. It was no Limbo or Shadow Complex (two games it reminded me of), but it was enjoyable.