The Missile Fever can only be utilized during the Egg Dealer boss fight. It is activated by hitting three slots on the Egg Dealer that correspond with the Missile Fever icon. When used, the Egg Dealer launches a volley of six missiles.
In gameplay, Dr. Eggman starts the battle with this attack. If the player is able to stop the third slot themselves, the missiles launched will attack the Egg Dealer, damaging it. If Eggman pulls this off, the missiles will go after the player. If the player continues to lose lives, Eggman will start the battle by accidentally launching Missile Fever on himself.