Miscellaneous Codes
Change some facets of the game by typing these codes at any of the tank screens during the game: "supermegaultra" will change the birth noise of the character Preggo, "time" will display the time on the tank and "zombie" will give all of the fish the appearance of undead creatures.
New Pets
By beating levels and advancing in the game, you can unlock new pets to raise. Get Stinky the Snail by beating Level 1-1. Earn Niko the Oyster by finishing Level 1-2. Play with Itchy the Swordfish after you conquer Level 1-3.
"Ho Ho Ho" Fish
Enter the virtual tank store and purchase a guppy. Name him "Santa." He will sing Christmas songs and bring you bags of shells, which are used like currency in the game.
Pass the Shells
You can give shells to yourself by creating two accounts in the game. After the second user account beats the first level you can go to the main menu and type "Give." This allows the second account to give the earned shells to the first account, increasing the amount of currency to spend in the game.
Sandbox Mode
Access the "sandbox mode" that gives you more freedom in building and maintaining your aquarium by pressing the arrow keys in this order while on the main menu after you have earned a silver trophy: "Up," "Up," "Down," "Down," "Left," "Right," "Left" and "Right." Then press "B," followed by "A."