YouTuber Hiiro has been developing laptop animations of soccer-playing mobile suits. Haro is the ball, whilst Ultraman and Kamen Rider are the refs.
The ensuing parody is delightful.
This is not a very first. In 1992, Banpresto released a soccer game for the Super Famicom named Battle Soccer: Field no Hasha in which Gundam mecha, Kamen Rider, Ultraman, Godzilla and other kaiju played each and every other in soccer.