Well, I finally got time to sit down and play through the last part of Limbo last night, and drop back and pick up some of the hidden eggs I missed.
 
I stand by everything I said in my review it's a great game.  Okay, yes it is a bit short and seems to end rather abruptly.  You don't get any sense of what is going on - even at the end.  Limbo is clearly a creative masterpiece, there's something about that is just 'right' in a way that Hydrophobia doesn't have.  I know they are totally different games I'm sure, but they are XBOX Live arcade releases that stand on innovation.  For some reason Hydrophobia fails, and Limbo succeeds.  Which is a shame, I really wanted to Like Hydrophobia, but now I find it choresome to play.
 
I think the voice acting doesn't help and the characters, apart from Kate aren't particularly great - I don't think Kate would win any awards, but she's at least likeable - unlike the annoying guy on the radio chatting to you in a regional accent....
 
The interesting thing is that despite the abstract nature of the boy in Limbo, I find myself caring about his fate significantly more than Kate in Hydrophobia.  With Kate, watching her drown is just an annoying time-sink while I wait to try again.  With the boy in Limbo, I genuinely don't want him to get hurt - I want him to succeed, i want him to find his sister... I feel sorry for him when he get's minced up.  
 
Why this is - isn't clear, it could be a wierd counter effect - like the uncanny valley, whereby we actually naturally empathise with more abstract characters.  Or could it be the clarity of the quest, and the sureness of purpose in Limbo - move right, avoid traps, solve puzzles - find sister.  Instead of run around corridors sloshing with water listening to some irritating guy give you advice in a regional accent.   Often in Hydrophobia, I enter a new area and think right, where am I supposed to go, what am I supposed to do?  The story is vague and somewhat soul-less to me.  It maybe suffers from over-complicatedness.
 
I haven't had the stamina to finish Hydrophobia yet, so maybe it will get better.  Now I've finished Limbo, I find myself a little sad.  Sad at the short-ness of the game to a degree - even though I will play through again I think.  More so - sad at the obvious futility of his quest.  I'd read reviews before - so I knew what happened, but when you see him running up the grassy bank and see his sister - you feel happy, you're glad he's made it... You want them to run up to each other and embrace...
 
They don't of course, the next time you see them is after the credits, as corpses with flies hovering around them.  What the developers are trying to say here I'm not sure, that there is no happy ending?  That the journey IS the happy ending and as soon it is over, all you have is oblivion? 
 
I think Peter Molenuex has thought along this line too, I find the prospect of Fable 3, exploring the 'happily ever after' which often gets omitted fascinating.  
 
It's a bit like life I suppose, when you are young you sort of expect to find someone, get married - have kids and live happily ever after... But there is no such thing, as one struggle ends another begins....