Stupid Invaders Trivia (Dreamcast)
In the bathroom in chapter one you can find the Sega Dreamcast logo.
The man who supplies the voice of Bolok, Billy West, is also responsible for supplying the voices of TV characters Fry (from Futurama) and Stimpy (from Ren & Stimpy).
The man who does the voice of Etno in Stupid Invaders is also the voice of Brain on the cartoon Pinky and the Brain.
Stupid Invaders is based on a short-lived animated series called Space Goofs and features the voices from the series.