It was definitely a bit disappointing. I enjoyed the game well enough and it's not like I expected it to be amazing, but I thought it would be better in terms of world design and mission variety. The world is small, empty, lifeless and homogeneous with absolutely nothing interesting going on, and the only good missions -- the ones involving orc captains or warchiefs -- are very repetitive. Since all of the warchiefs and captains are just regular orcs with more health and immunity to certain attacks, challenging one at the beginning of the game feels more or less the same as challenging one towards the end. Also, those final missions are pretty damn bad with all the awful QTE and stealth stuff.
And then we have the issues I actually expected, like the awkwardness of the Nemesis system (it's a great concept and I hope other developers will try similar things, but the way it's implemented with that lame menu that keeps popping out and pulling you out of the experience... it's not great) and the simplicity of the combat (visually it's excellent, with really fluid and brutal animations, great dramatic zooms and slow motion effects etc. but from a mechanical standpoint this Arkham combat system is just as mediocre as it's always been).
I mean, it's not a terrible game by any stretch of the imagination, but the demos I had seen certainly had me hoping for something better than what I actually got.