Splatoon Enter the Alter-verse: Rift in Time

An astronaut, Brendan Bower is tasked with maintaining the Kamabo Company satellites but is caught in a mysterious cosmic storm along with his crew, only escape into a capsule and crash back to the Earth below, only to fall unconscious form the impact due to a head injury. Unknown to him, it is no longer the current year but way into the future, thousands of years after humanity nearly nuked itself out of existence. He is found and recovered by a race of octopus-based life forms and brought back to their base. He soon finds out when he is awake, he has lost his memory and discovers the cephalopod-like creatures that took him, wanting to get answers as to what had happened once, they find a way to communicate with each other.