"One, visit 15 different time periods. Two, meet interesting historical figures. Three, kill them." Fallout co-creator and prolific RPG programmer Tim Cain's YouTube channel is a treasure trove of what-if stories. What if WildStar had shown up to the MMO craze just a few years earlier? What if Interplay made Fallout 3 instead of Bethesda? What if THAC0 wasn't so egregiously confusing that Cain's encyclopedic knowledge of it didn't get him hired at Interplay in the first place? They're all worth the watch if you fancy yourself an RPG gamedev loremaster—but yesterday, Cain talked about one of his wildest what-ifs yet. In his most recent video, Cain discussed Time Walker—a proposal for a first-person RPG he drafted at Troika with fellow RPG veteran Jason Anderson, who worked with him on games like Fallout and Vampire: The Masquerade – Bloodlines. While the game never came to be, even in the form of a prototype or more elaborate pitch, it sounds ludicrously ambitious even today. In Time Walker, you'd play a "temporal agent" traveling through time and completing missions to ensure your own reality's existence as enemy agents try to rewrite history. As the timeline becomes less and less stable, your gear becomes "more fantastic and improbable," but mess things up too much and your reality poofs out of existence. Once you guarantee the existence of your reality, you beat the game, but if your reality ever becomes impossible, you "cease to exist." Horrifying! "Feature bullets, these are great," Cain laughed in the video. "One, visit 15 different time periods. Two, meet interesting historical figures. Three, kill them." Some example missions he mentioned involved assassinating a pharaoh in ancient Egypt, giving a young girl a specific doll on her eighth birthday (presumably as part of some shenanigans involving the butterfly effect), and creating a paradox by preventing the invention of time travel. The way your timeline's likelihood of existence would balance gameplay