I beat the computer in Metal Gear (the first one) on PC from GOG. I saved immediately after and before the Big Boss fight I had to put the game down. I came back and realized I was locked in the room and couldn't progress. I don't have any other saves because I assumed that the game would fucking work. I don't wanna run through some of the most nonsensical puzzles I've seen all over again so is there anything I can do?