The only problem i see with a screensaver is when Fish Tycoon is on screensaver the game is on pause "but they still move" whereas this game would have to be unpaused so they could move and fish and counters will go up and down and etc. It would only work if the game was running which wouldnt work for a lot of people who pause when not playing. Maybe as a default it could run the game on slow or something i dunno. It would be cool never the less.

Actually, the screensaver function of Fish Tycoon does not pause the game. It merely displays the state of your tanks in whatever game speed is currently set. It is equally true that if you have the game set to pause, the fish still move. That's not the case in Virtual Villagers.