I bought the game and have played for 82 minutes according to Steam.

The single player is very fun so far. I've had no problems with meelee or ranged fighting and it all looks very nice.The AI isn't completely idiotic, the Orks are good at hiding behind objects and trying to run around you so you can't shoot 'em down. Unless there's many of them, in which case they just come storming at you.
I've only lightly touched the multiplayer so far, but it was definetely difficult.

It's fun!