Original: The player takes on the role of an engineer named Isaac Clarke , who battles a polymorphic , virus-like , alien infestation which turns humans into grotesque alien monsters called '' Necromorphs '' , on board a stricken interstellar mining ship named the USG Ishimura .
Simplified: The player plays as an engineer named Isaac Clarke , who fights against an alien infestation which turns humans into monsters called '' Necromorphs '' , on a mining ship in space named the USG Ishimura .