When Fish Tycoon first came out, I played for a couple minutes and didn’t get the appeal. I was heading up the marketing team at Oberon Media at the time and we relied heavily on analytics to help guide what games were going to get the majority of our promotional efforts, but before we put it up on the sites to see what games clicked with our users, we often played the games ourselves. While I didn’t think much of the game, a funny thing happened every time I walked through the marketing department: I kept seeing Fish Tycoon on everyone’s screen. That’s when I realized we had something here: the birth of the sim genre in the download casual game space.

Fast forward three years and TallTree Games has launched Fish World on Facebook, following in the steps of sim games like current #1 FarmVille (15 million daily active users), #3 Farm Town (5.8 mil DAU), and #5 Restaurant City (4.1 mil DAU). Fish World is about to cross into the top 20 applications on Facebook with over 1.3 million DAU in just under three weeks. And it’s already caught Playfish’s latest sim offering, Country Story (another farm sim game) which appears to have reached a plateau in users after launching only five weeks ago (see chart at right).

Why the success for Fish Town? A lot of factors:

• It has a very short time requirement to play for each session – which matches the broader Facebook demographic of a user who may check in periodically during the day but can’t spend a lot of time playing a game
• It taps into Facebook’s female skewing audience (Quantcast shows Facebook’s US visitors are 54% female) by tapping into the nurturing game-play preference
• It has a proven casual game successor in Fish Tycoon
• It has taken the viral “gift giving” request and achievements to brag about to friends (similar to Zynga’s top FarmVille and Mafia Wars games) to help spread the audience
• A good extendable platform to drive revenues by offering different fish (they just launched Halloween themed fish), tank items, and backgrounds – a longer term key for revenue generation will be game-play specific items (like automated/timed feeders or mass fish sales versus the one-by-one nature now) designed to make it easier to play.

If Facebook games continue to follow the path of the download casual game business, we should see a Virtual Villagers-style sim game soon, which has a great deal of possibilities. After that, the next “big thing” in casual games was the I-spy like “hidden object” genre, defined by Mystery Case Files and then later by Agatha Christie and Women’s Murder Club. Again, heavily female skewed which is a good match, but these games are not quick plays (often taking 15 to 20 minutes just to find the items on a single screen), and have limited virtual items (other than potentially paying for clues or better devices to find things).

What do you think the next big genre on Facebook will be? Or are we destined for more sim games?