Playing a bunch of Pokemon Showdown eventually led me to this.
Pretty hard to play without a USB controller, but basically it's a fighting game, ala streetfighter. Except that all of the characters are pokemon: I strongly reccommend using Gardevoir or Breloom. It's neither a finished nor a deep game, but it's mind-numbingly fun. I guess it was also made by the animators of the actual pokemon anime.