You have to dig really far into the past to find anything by Kojima(other than Zone of the Enders) that is non-Metal Gear related. The popularity of MGS basically gave Kojima his own studio at Konami with what seems the sole focus of making more Metal Gear games. Not that this is a bad thing per se considering most of them(atleast all the numbered ones) are really good. I think Kojima's greatest achievement is popularizing a cinematic approach to storytelling in videogames that is consistent with the rest of the game. Creating a true cinematic experience at a time this was still a novelty. Also Kojima has a penchant for adding neat little details into his games as well as creating an eclectic mix of anime sci-fi and real world seriousness.
I would consider Shinji Mikami a definite visionary as well. The way Kojima re-invented storytelling in games Mikami re-invented survival horror and third person shooters.
I would consider Shinji Mikami a definite visionary as well. The way Kojima re-invented storytelling in games Mikami re-invented survival horror and third person shooters.