Unlocks 2 secret characters: Human Smoke and Khameleon.
Also unlocks 2 extra menus in the Options (Blue and Red question mark icons).
Make sure to apply the patch on the Rev 2 of the game.
Database match: Mortal Kombat Trilogy (USA) (Rev 2)
Database: No-Intro: Nintendo 64 (v. 20210220-053642)
File/ROM SHA-1: 11F2488B21F9F7185C25905DD02C2955C35AD5C1
File/ROM CRC32: 0F323D00