Well, as it turns out, you have to play through the game at least four times. The alternate scenes are:
When you're fighting The End, and your final duel with Ocelot.
THE END:
- Beat him normally.
- Beat him by saving, quitting out, and then setting your clock several weeks forward.
There's also:
- Letting your stamina drain down.
- Saving, quitting out, and setting your system clock forward a day.
OCELOT:
- Pick the left gun, shoot Ocelot.
- Pick the left gun, miss Ocelot.
- Pick the left gun, don't fire.
- Pick the right gun.
When you've unlocked all the of the videos in DEMO THEATER, you get access to the PEEP SHOW. Which is all the scenes in the game with semi-nudity.