I bought the game 3 days ago, and I'm having fun with the singleplayer mode. How much different is the game play for multiplayer?

Also, I'd like to join the n00bfest server to check out the multiplayer features.

Honestly, it's not a whole lot different than the single-player version other than interacting with other people.

It's pretty much "Hey, check out this giant penis statue I built!" and then someone runs over to you and tries to climb on the tip.

Well there's more to it than that. All jokes aside, it's cool to interact with others.