I think that the protagonist fell down the ladder when he was going into his bunker (perhaps because of the shockwave generated by the bomb) and got a head injury. He was unconscious for a long time, explaining how the radiation cleared and so much else happened while he was in there, and he woke up with amnesia.
 "Medieval Chronicles 7"){kind=icon}
 "Medieval Cop 9 -Song & Silence- (Part 2)"){kind=icon}
 "Alxemy"){kind=icon}
 "The Last Door: Prologue"){kind=icon}
 "Time to wake up"){kind=icon}
 "OTOMACO"){kind=icon}
 "Space Oddity 2"){kind=icon}
 "Space Oddity"){kind=icon}
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 "The Fog Fall 3"){kind=icon}
 "Fog Fall 2"){kind=icon}
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 "Morningstar"){kind=icon}
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