Although they remain uncredited, Bandai Namco Contributed to ARMS' Development.

"For Nintendo Switch game 'ARMS', released in July 16, 2017, we produced approximately half of visual assets for stages, fighters and arms."
-Products Page, Bandai Namco Website

The concept for Twintelle was presented when game director Kosuke Yabuki wanted a character that fought with their hair. To make sure she had a distinctly non-Japanese background, the designers spoke with people in different regions of Nintendo and gauged audience feedback.

To make the game stand out from other fighting games, the initial concept for the game had the camera positioned behind the player character. However, it was really hard for the player to judge distances. They solved this problem making the arms extend, which lead to the unique idea for the game.

The early idea of the game was to feature staple Nintendo characters such as Link and Mario. The aesthetic of the game clashed with them, and it was eventually decided that a new cast of characters be created. Character designs started with the arms first with the team working backward to decide what type of character would possess it. However, there are some exceptions where a design came first.

An early concept for the game had the characters using external devices to punch their opponents, however, this was later dropped in favor of the characters extending their actual arms.

According to the game's Art Director, Masaaki Ishikawa, the Dragon Ball and Akira series were largely influencial to the game's art style.