Tool-assisted movies (1)

This game, ostensibly a spin-off of the Contra series, began life as a completely unrelated game, yet still manages to invoke the spirit of the other games in being an insanely difficult, one-hit-kills-you shooter.

Contra Force offers a selection of one of four characters, a jumping glitch involving the pause screen, and lots and lots of lag - and yet the game is still completed remarkably quickly.