Dirty Pair:Project Eden

[Berry]

After the game has been paused for around 20 minutes, 23 seconds, a long beep will play and a telephone ring will repeat indefinitely.
Programmer Yujix Terada did similar things in Taito Chase H.Q. and Gokuraku! Chuuka Taisen for the TurboGrafx-16/PC Engine.

http://tcrf.net/images/e/ea/DirtyPair-Telephone.ogg



Yujix Terada also "hid" his name at the very bottom of the screen during gameplay. Most NTSC televisions at the time would cut off this part of the screen.