[drb493]

Seaman for dreamcast utilized a microphone in which you would talk to your fish (that also would develop to grow a human head). It relied on voice commands. You could praise it, scold it, order it to clean its tank. In response it would insult you or ask you trivia facts.

The game also used the dreamcast clock to age the fish even when the game was not running. It had an anti-cheat mechanism where it would detect if you altered the clock and would punish the cheater accordingly.