This video is a documentary intro, and even though 1) the creators are German, 2) they show Mario peeing and 3) everyone has sex at the end, it still doesn't explain what's going on.

You're just gonna have to see this for yourself - but it's more than 5 minutes long, and doesn't start getting weird until Ron Jeremy Mario pops out of a Space Invaders tank at 1:40.

There is no actual nudity, but I'd still classify this as rated nsfw for: Ryu and Guile making bedroom eyes; hot Pong ball-on-paddle action, and Lara Croft having a shampoo-commercial orgasm.

Video Games by MUSCLEBEAVER [Vimeo via GoNintendo, thanks tipster Morris]