Brutal Legend's development was marred by a series of unfortunate incidents involving IP rights, but eventually, it hit the market. Sadly, we haven't seen anything indicating that we'd ever get to return to the world, outside of the occasional comment by Tim Schafer, who recently spoke up again regarding his creation.
Schafer states, "I love that world and I would love to go back there. And I think [actor Jack Black] might be up for it, too. I would love to...even just do a DLC pack. We're always trying to get Lionwhyte in there, [as] a playable Lionwhyte army. Maybe that would happen some day." I would definitely be up for it as well -- if all of the RTS elements were eliminated.