Its pretty good. I thought they nailed the arm components really well, after you get the hang of it all. The story had a pretty good basis, though it was a bit funny and felt like it could use a few more hours. But in terms of gameplay, I thought it was pretty fun. Like i said, the arm is great, you can do a lot of things with it, and I hope other people use a similar grapple mechanic because it can work with a lot of gameplay styles. the weakest parts of the game that it feels a bit too linear and it can be pretty frustrating sometimes when you can fall into water and die, or run into radiation and die. I thought these kinds of pits and invisible walls were starting to drop off finally, but i guess not. Combat is far from great, they made a lot of decisions with weapons that I thought were bad, they run out of ammo quickly, and you can't pick them up except from drop pods. But when you're swinging around picking off solders one by one, its pretty fun actually. it needs refinement though, and consequentially, I doubt multiplayer will be anything noteworthy.
All said and done, Bionic Command obviously focused on getting the arm mechanics down, and they really nailed it, but at the expense of just about everything else. I thought Bionic Commando was a good game, but its not great. If you have a lot of cash floating around, its a good game to pick up, but it might be a better rental or used game.