SILENT HILL 2

To get this ending, you'll need to start a New Game Plus playthrough and find a new item: the Dog Key. To get it, you'll need to scour the town of Silent Hill whenever you have the chance to search its streets before you complete Brookhaven Hotel. First, check out Big Jay's Pet Shop on the corner of Katz Street and Neely Street before heading to the Wood Side Apartments. In the back room of the shop, inside a pet carrier, you'll find the Broken Key Part.
After visiting Rosewater Park and meeting Maria, you will have access to the streets of Silent Hill again, albeit in a new area. Keep an eye on the surrounding area to keep an eye out for a gate marked with a bone.
Look behind the gate and find a small courtyard where you will find a dog house . Inside you will find the second item, another broken key part.
Combine the two items to make a complete key. Save it until you reach the Lakeview Hotel at the end of the game, and after watching James' videotape, use it to open the nearby surveillance room.

You can do it in one playthrough of NG+ by saving in advance near the music machine on the first floor of the hotel. Open the dog's room with the key, Observation Chamber, and there will be a cutscene.