I thought it was in the basement after it was flooded (You can drain the basement, it's a side-quest puzzle that doesn't even get marked on your quest log) Pro tip : When looking for gameboys and 8-Bit OSTs, search near the end of a patient's tape, or in your case, the start of your journey near the end-game, as it only appears once you finish the red tape.
@@RedRan6er Been a while since I've last played, so I am probably gonna forget some things. Once you complete Max's tape, the basement should be flooded. Go down there, and crouch in the elevator. You should hopefully get a clear shot down the stairs, because there should be an explosive barrel floating in the water, which will break the boxes allowing you to go into the intersection. I think you then need to go to the room with the workbench where you made the pistol, and shoot another explosive barrel down the hallway towards where you got the flashlight. Go into the flashlight room, into the vent, and you should be able to toss a pill over the fence and into some explosive fluid, which will drain the basement a bit. Then, head back to the room you started this whole adventure in, and shoot one last barrel to fully drain the basement.
Honestly really good, still don't understand how it survived all that Rainbow stuff but it's all in Desmond's mind so I guess it can work idk ¯\_(ツ)_/¯
