Why do characters in the 1989 game "Prince of Persia" move so smoothly?

Those 9x and earlier may have played this game on computers running MS-DOS, NES, Sega. Besides the attractive storyline and gameplay, have you ever wondered why Prince of Persia has very smooth motion graphics and is completely different from other games of the same time? That's thanks to the rotoscoping technique - a technique often used in animation in which people record live action, then project the video onto a glass board and the artist traces each frame on paper to get the most accurate movement.

Prince of Persia was designed by Jordan Mechner and before creating this legendary game, he developed another, equally familiar game, Karateka (1984) - a very popular martial arts game on the NES with the main character being a Karate fighter who rescues the princess by defeating boss after boss. The character's movements in Karateka are also very smooth, especially the back and forth cross-legged movements and the very realistic Geri kicks. This is the first game designed by Mechner with rotoscoping technique.

With Prince of Persia, Mechner asked his younger brother David dressed in white to perform movements for the main character such as walking, running, high jumping, long jumping, rolling, etc. to return to the reference video. In addition, he also asked relatives to act in some scenes and used sword fighting scenes between Errol Flynn and Basil Rathbone in The Adventures of Robin Hood. The result as we can see is that the character's movements in Prince of Persia are very realistic and it contributes to creating a unique playing experience when we always feel the uncertainty and danger when controlling the character to jump over obstacles, pits or climb walls.

Although considered a pioneer in using rotoscoping in game development, Mechner revealed: "When I started with Prince of Persia, I didn't think about doing it as a pioneer. I used rotoscoping mainly because I'm not good at drawing or animation. It was the only way I could think of to get vivid movement for the character."

Prince of Persia was programmed in the low-level machine programming language 6502 and was initially released for the Apple II and Commodore 64, with an MS-DOS version released in April 1990. The graphics and sound of the MS-DOS version were used as the original for porting to other platforms due to its better quality compared to the original version running on the Apple II. Ports for other computer systems and game consoles were released from 1990 to 1994, such as Amiga, Atari ST, X68000, Amstrad to Game Boy, Game Boy Color, Super NES, NES, Sega CD, Sega Master System, Sega Game Gear, Sega Genesis. By 2007, Prince of Persia was released on new generation systems by Gameloft such as Xbox 360, PS3 and later by Ubisoft on mobile platforms such as iOS and Android. Although not the best-selling game in history, Prince of Persia 1989 has significantly influenced the cinematic platformer genre such as Another World, Flashback or later action adventure games such as Tomb Raider and Assassin's Creed. Wikipedia