In the online mode, only racing and freestyle games may be played, which is a shame as hockey is arguably the best multiplayer mode. This could possibly change due to the online nature of the game, but it's not currently there. Only having two modes left me wishing for more. Another caveat: You can play online or you can play multiplayer with your friends, but not both at the same time. In other words, for every PS2 playing online, there's only one player online as well.
Playing over my cable modem connection, broadband went seamlessly. I experienced no lag whatsoever and only had problems when the host of the game got dropped. My PS2 even froze once, but other than that, there were no major problems. Finding games is a snap, though most of the time I played there were only about 20 games or so going on. That's around 80 people max. And since there's no joining a game once it has started, you may be waiting to be setup with other players for a while, even if you choose to host your own game.
The biggest problem with the multiplayer mode is the profile points. You can earn enough profile points to buy the most expensive ATV in the game and crush everyone. That alone would seem to make the single-player experience worthwhile. However, after just getting the game, I noticed that most online players had the best ATV and were constantly lapping me even though I was driving pretty well. There is a cheat code that unlocks everything, even for multiplayer. If you're a newbie who doesn't know about that code, you're not going to win online. If you've gone through the single-player mode to earn all the profile points you can, you'll feel cheated that someone could just enter in a code to get where you are.
The online aspect of ATV2 is really its selling point. The graphics have gotten just a little bit more detailed, but the game essentially looks identical to its predecessor. The environments are painstakingly stagnant, where even birds flying by just don't make it feel alive. There's just not a lot going on, and there's nothing at all to break or interact with, other than dirt.
The sound is very good, with engines "vrooming" everywhere. The music is king, though, with awesome tracks by Cypress Hill, Alien Ant Farm, Garbage, System of a Down, Korn and Coolio, among many others. In fact, the soundtrack may be better than the game itself.
If you own the original ATV Offroad Fury, other than hockey mode, there's not much to recommend here unless you absolutely loved the original. If you've gotten the PS2 Network Adaptor, then you may be interested in playing online, but since online play isn't as good as playing with some friends through a Multitap, you won't be compelled to keep signing on. Still, there's plenty to do and tons to unlock if you don't use the code, that is.