Pretty damn good.
SP good stuff:
nice variety of missions
great combat
good feeling of genuine combat mayhem with a nice mix of solo / part of a team dynamics
okay plot - mix of in the team with high level Helghast power struggles serves as an okay backdrop to the gameplay
SP could be better stuff:
plot isn't developed well enough though given the setup, and too many characters remain too paper thin
ending is definately too abrupt - although you could say the same of KZ2 so I guess it's GG style
cutscenes are in-game engine so more consistent than the - superb - CGI cutscenes in KZ2, but the encoding is oddly weak - lot's of blocking when they transition in/out. Nothing major but odd in such an otherwise graphicall polished title
MP
pretty good so far. like it although miss some of the options from KZ2. hopefully these will be patched in
Coop
lots of fun
Botzone - yup, tried it
very good bots I thought. I guess there's minimal actual need to use this mode - given you gain no experience - but I think all MP titles should have bots so I'm glad to see them there. A great way to learn maps and have a few quick matches before going online. Also nice for territories with patchier connections.
Best bit overall - the Jungle mission in SP. Liked it a lot and nice to actually have a truly alien feeling environment. I understand why - like Avatar in the movies - there is a tempation to make games more broadly appealing by making environments / aliens more familiar to our Earth trained eyes, but damn given you can have near enough any setting in a game I want to see more "different" environments, and the Helghan jungle delivered nicely. Jungle enough to be familiar, but different enough to be exotic and interesting to jaded eyes.
Try to be reasonable... its easier than you think...