Hotline Miami stores unlocked weapons/masks/levels and level scores inside a single file. This file is located in hotline_miami (game's main directory) with the filename "saves.dat". This file may be easily edited to unlock weapons, masks etc. via the use of a text editor such as notepad.
Before making any edits to saves.dat, create a backup copy of it in a safe location in case anything should go wrong.
Some of the achievement progress is stored in a separate file called achievements.dat. This file is just as editable as saves.dat
- Setting the overall score or changing the unlocked weapons can screw up the weapon unlock progression. The game may end up thinking that a negative amount is required to unlock a weapon.
- (Steam) Achievements may not register properly if the achievement's condition was satisfied during save file editing rather than during gameplay.