In Chapter 4 Stage 2, there is a room with a of Alastor and Another Joe in a yellow costume. In the first Viewtiful Joe game, before the fight with Another Joe, Joe makes a bet between the two that whoever loses most wear his costume in yellow.
Contributed by Valkan95
Alastor reflects his lightning off of statues during his fight. The statues are of Gran Bruce, a boss from the first Viewtiful Joe.
Contributed by Takahashi2212
The demo for Viewtiful Joe 2 on the PS2 Holiday 2004 Demo Disc contained a glitch that would erase the player's memory card.
Contributed by Pogue-Mahone
In early trailers, a multiplayer mode was shown off. One player would play as Joe while the other player would play as Silvia. However, sometime during development, the mode was dropped.
Contributed by gamemaster1991