It should be totally different - I am not going to use your graphics or music- I make my own for that.
The only thing I am not sure is how much you care about the story. I mean Submachine is your idea- therefore I can't name my game Submachine. I am just concerned about when I write the story that I have too much of the same. It sounds like a copy to me if I do a game based on another game - but it is still all by me - do you know what I mean? What about the Theories in the Subnet? Do I need a consent from you or the people who wrote the theories to embed them into my game? A precaution is always that I can write your name and your game in the credits - but that's something that I have to ask you.
How about:
Mr. M lost his foot in a wrestling battle, but it wasn't so tragic- he found a new foot , an even better one.
Player: OMG? KARMA FOOT???
Narrator: NOOOOOO! He gained a Cyborg foot and his new power was kicking Butts. Butts especially from Patreon supported artists.
Player: OMG THIS STORY IS SO GOOD- I am going to be a Patreon of this guy!
Narrator: And the cycle of butthurt begins....
Narrator: In the deep hole- there was a machine...
Player: SUBMACHINE?
Narrator: NOOOOOOOO! It was my washer where I forgot my laundryyyyyyyyy!!!!!
Player: ...
Narrator: MY BIG STINCKY LAUNDRYYYYYYY....
Player: ...
Narrator: And it was a Portal to...
Player: OMG, Karma Portal?
Narrator: to the interdimensional...
Player: YES; OH YESSS!!!
Narrator: noncomprehensible...
Player: OHHHHHH
Narrator: sentient beeing....
Player: ..... DDDD::::
Narrator: ... also know as my son of a bitch crazy ass wife!
Player: ...
Narrator: ...
You know, If I could, I would totally quit my Job - but the scriptwriter is one heartless kind of a man- he likes to see me suffer ;_;
Player: I feel you.