Doom

How many instructions does a processor need to execute to get through the first level of Doom?  About 2.7 billion, in my case.  Over the course of the several minutes it took me to stumble through the level, it rendered about 1080 frames, each of which required about 2.5 million instructions to produce. The other 700 million instructions initialized the game, loading textures, setting up data structures, etc.