Fish Tycoon hands-on at IGN.

"Quick, off the top of your head, name all the Tycoon games! If your answer didn't start with "Railroad Tycoon" you're probably too young to remember the days when Tycoon games didn't exist. Back then gamers had to play Sim games, and they had to walk 15 miles in the snow to buy them! Where were we? Oh right, Tycoon games. More specifically new Tycoon games, and even more specifically, Fish Tycoon for the Nintendo DS. Majesco brought us a copy and dipped our fins into the aquarium sim turned fish-profiteering title."

Full Source: IGN