Set the Dreamcast's system date ahead several days for faster evolution. However, the tank will also not be maintained for that amount of time.
Quick evolution into Gillman stage
While playing the game, you will see a shell at the bottom of the tank. Keep tapping the shell until it starts to eat your newborn Seaman. After they are eaten, tap the shell more until the squid completely comes out. It will squirm, and eventually after tapping it enough, it will die and the baby Seaman will appear and will be in the next stage (Gillman). Hold A while talking into the microphone to speak to your Seaman.
Talking to your Seaman
It is good to talk to your Seaman frequently. You need to teach them how to talk. Try to talk as clear as possible. Hold the A and talk into the microphone. The Gillman stage is the stage when it will first start to talk. Use these words when talking to your Seaman: Hi, Hello, Hey, No, Yes, Seaman, Fish, Fun, Play, (and more). Experiment, but do not call it bad name or it will become unhappy. Also, remember to feed it in the morning and at night (two times every day).
Infinite food
Note: This trick requires two VMUs. Start and save a new game using a second VMU. Connect this VMU to a VMU that has an ongoing game. Transfer the food from the new game to the ongoing game. Repeat this as needed for unlimited food.
Drain the aquarium
When the seaman gets old enough he will help you move the rock to drain the aquarium.
Give your Seaman a new name
After naming your Seaman the first time, repeatedly ask "Do you love me?". Eventually, you will be able to change your Seaman's name.
Hypnotize Seaman
Select a Seaman and move the Analog-stick in circles around its head.
Move rocks
Press X + R and press Left or Right when over a rock to move it.
Hidden audio
Place the game disc in an audio CD player and play track two to hear a hidden message.
Keep him happy
Whenever you put the clock ahead on the VMU and you get back to where you left off except for a day or two later, add air and fix the heater. Then put the gillmen in a good mood! When you leave for that long they get mad and when they grow up, if you had never tickled them then they are very moody.
