It's pretty bad, especially if you've played a good FPS multiplayer. After playing Halo 2 I love Matchmaking, there's nothing that even resembles Matchmaking in Commando. Players are not penalized whatsoever for leaving in the middle of games, so they do, quite often. There is no method whatsoever to balance teams, anyone can join whichever team they choose no matter how many players are already on the team.
Figuring out who is actually on your team and isn't is also loads of fun since the opposing teams don't have silly things like different colors or anything stupid like that.
I love the Campaign mode, it's fun, it's challenging, and when I first got the game I couldn't even pull myself away from it to try out the online mode. But finally after hours of playing I went online and started playing. I think I played 2 games, the first one was me vs. this other guy, then a few other people showed up so there was like 7 people on the other team and 2 people on my team. After that I played one more game and the other people on my team wanted to group up and play a few more but I couldn't even stomach myself through another game.