Gunvalkyrie is an action game that takes place in an alternate Earth where space travel and other technological wonders were made possible in the 19th century. Traveling to the British Empire's colony world Tir na Nog, you must locate Dr. Hebble who has disappeared under mysterious circumstances. You acquire payment depending on how well you perform during missions. Money can be used to upgrade your character and their weapons.
Smilebit was originally going to release Gunvalkyrie for the Sega Dreamcast. The early demise of the Dreamcast pushed development to the Xbox. In addition, early on Gunvalkyrie was going to incorporate a light-gun into the gameplay but this was ultimately scrapped.