There are many special achievements in "Silent Hill 2: Remastered (SILENT HILL 2)", Tin Hat is one of them, and the requirement to achieve this achievement is to achieve the UFO ending, and to do this ending you must It can only be done in two weeks or more.
How to get the Tin Hat achievement in Silent Hill 2
tin hat
Complete UFO ending
To reach the "UFO" ending, you must play through multiple playthroughs, find blue gems, and investigate (via the inventory) near the four UFO symbols hidden throughout the game. Sapphires can be found in the display windows of Neely Street jewelry stores in the South Valley, just north of Big Jay's.
The first symbol is hidden on the roof of the Sol Street Apartments in South Valley.
The second symbol is hidden on the dock in the Rosewater section of South Valley.
The third symbol is at the Lakeview Hotel Garden Pier.
The fourth symbol is in Room 312 of the Lakeview Hotel.