Dissapointing
I decided to play the demo to see if it was everything I had read about, early on in the demo I started getting tired of the game. The control setup could have been better, the graphics are ok but nothing spectacular, the enviroment was reasonable but didn't give me the feeling that other game enviroments have and last but not least the worst in my opinion is the aiming/shooting in the game, I found it to be extremly frustrating, they seem to have made it harder then normal to actually shoot someone, be it with the bow or a shotgun. The best part of the game I would have to say are the dinosaurs, who doesn't love killing off huge and small predatorial dinosaurs...
To shorten it up, if you like killing dinosaurs and don't mind ignoring the "bad", then this is your best option.
Now if you worry about gameplay,grafics and story ( didn't seem to be anything great, a slight ripoff of farcry in my opinion ) then look elsewhere.