Hidden Monsters:
(You can access these hidden monsters by completing certain monsters all
the way to Tokyo's three stages.)
Play as Godzilla 1st- Beat the game with the basic Godzilla.
Play as Godzilla USA- Beat the game with Godzilla 1st.
Play as Minilla- Beat the game with Godzilla USA.
Play as Dr. Serizawa- Beat the game with Minilla.