The Game That Needs No Introduction

This post is inspired by some thoughts I had in response to Charley’s post about cut-scenes and ‘non-game’ moments. It occured to me that I could not think of one videogame that had no introduction of any kind. In other words, no starting tutorial or beginning cinematic, not even a start screen. Can anyone think of a video game that begins in media res? A game that you install, or load into the disc drive, or shove in the cart, and it just starts without any warning whatsoever?