Galactus is a boss in Marvel: Ultimate Alliance.
Marvel Ultimate Alliance
For the second phase of the operation to steal back Odin's power from Doctor Doom, the heroes head to the Skrull Homeworld where Galactus is attacking to consume its energy. The purpose is to steal Galactus' Muonic inducer which he utilizes with Optronic Drills to prepare a targeted planet for consumption. Incensed by the Ultimate Alliance interfering, Galactus gives pursuit until they are rescued by Silver Surfer, a former Galactus Herald. With the surfer's help, the heroes defeat Galactus and steal the Inducer while he is incapacitated. The survival of the Skrull homeworld depends on whether the Optronic Drills are rendered useless.
Either way, after the war against Doctor Doom is won by the heroes, Galactus swears retaliation against Earth.