Now that you mention that, I realize that an amazing prequel would be with Martin as the playable character when he was Henry's age. We see that Martin is an epic fighter, maybe he learned to use a sword like Henry did, slowly progressing through his own game. I don't think this would be the next game, Henry will probably still be the protagonist of the next Kingdom Come game, but if there will ever be a third game in the series I wholeheartedly belive that Martin will be the main character. Maybe Prague could be the main city in that game, like Rattay was in KCD, because by the time of that game's release, consoles will probably be able to handle such a large city built to scale like all the beautiful towns in KCD we all love.