I thought this page was mostly geometry+shaders. But the snap version has lots of interactivity! You can trigger lots of the stuff you could trigger in the game. Have they replicated all that manually or how?
In the game, these are actually two separate entities, and I haven't done anything to prevent the "kicked" one from immediately spawning in the air here https://noclip.website/#snap/1A;ShareData=AUsPn92;%5eVT:h=19... , or to hook up the first one to the second (although the system to signal between distant pokemon, which it probably uses, is mostly implemented). There are a few other instances of things that are supposed to be spawning conditionally which aren't handled yet, like extra lapras in the beach.