International Karate + (also known as IK+, or Chop N' Drop in the US) is a side-view karate fighting game created by System 3 initially for 8-bit platforms (Commodore 64, ZX Spectrum, Amstrad CPC) and then ported to Amiga and Atari ST in 1988.
In this iconic beat 'em up, three "karatekas" compete on a beautiful Japanese beach. Up to 2 of them can be controlled by human players. The fighters have at their disposal several moves, including kicks, fists, headbutt and more. The designer and programmer, Archer Maclean, made brilliant use of the simple one-button joysticks: each of the eight directions of the joystick performs a different move or attack (e.g., up-right = fist). When the button is pressed, the action is different (e.g., up with button = forward kick with jump). Some movements also change depending on the direction in which the fighter is looking.
The animations are probably one of the best aspects of the game. To draw the frames of the backflip animation, Maclean manually copied, from the TV, the moves of the dancers in the film "Grease." Sounds were sampled from Bruce Lee's 1973 movie Enter the Dragon.
The only part not made by Archer Maclean was the music: the original C64 music was written by legendary 8-bit composer Rob Hubbard, while the Amiga version was signed by the - also legendary - David Lowe.