Old-Time ShyGuy isn't particularly easy. He has no attacks, but runs from Mario upon sight. If Mario fails to catch him in 15 seconds or less, he loses all of his lives instantly (no matters how much he had), thus causing a Game Over, and since there are no SavePoints in Heinous HQ, you have to start over the entire world over again in this case. When caught, Old-Time ShyGuy will send enemies at Mario. When caught again, his mask falls off (though his face is not seen) and he atrophies (implying his death).
- Despite him being very difficult, he's the easiest of all bosses in Heinous HQ.
- Old-Time ShyGuy is the only villain in the series to evaporate upon defeat.
- Old-Time ShyGuy wasn't seen elsewhere in the game, the reason why he was hostile was possibly because he "tried" to safeguard Heinous HQ.
- However, his cowardly and attempts to evade Mario deny this.
- Old-Time Shy Guy made a brief cameo in Super Mario 128, implying that Super Mario 64 Bloopers: The Videogame took place after Super Mario 128.