Ironball is a friend and fellow bounty hunter of Agent Citron. Ironball is an Iron Citron. The player is sent on a mission from Agent Citron to free and team-up with Ironball so the player and Ironball can defeat a bounty on a S.H.R.IMP and his mech.
The player first finds Ironball in a cage, which the Jail Key to free Ironball is being held by a Robo-Zombie. Once the player defeats the zombie and can pick up the Jail Key, the player goes and frees Ironball.
After a short talk, Ironball and the player start walking down to the docks, where the S.H.R.IMP is located. Ironball and the player start attacking it. After it is defeated, Ironball is not seen again in this mission, thus destroying the Imp to complete the mission.
- Its name is a reference of Thunderball, a villain from the 007 movie of the same name.