Honestly, how fun is this game?  I'd been thinking about getting it, but after playing the demo, it seems that all you do is hit Y and X until you can use a takedown move, then you watch a cutscene.  Does the combat get any more varied, or is it like this throughout the entire game?

Thats pretty much all it is, shooting sections aside.
And the gun play in my book is kind of clunky.
It'd make a good rental perhaps. If you can find it cheap it might also be worth while.

I paid full price for it and kinda wish I hadn't.

Isn't a bad game though.
Just somewhat repetitive and short.

Yeah, I'lll probably rent it as lots of people says I should be able to finish it in a day.  Thanks for your input.

It's definitely a good rental, even if the hand-to-hand combat basically boils down to "Block, wait, and do a quicktime event."

 
You should rent it,but its not worth the money.
 
 
I played it,slow combat and shitty environment,and hard as fuck.

Absolutely a rental. It's a love-hate sort of game. I hated it. I found the combat very tedious, and even on the normal difficulty it gets pretty brutal.