I don't remember much, and what I do remember feels very vague in my head, but I've been extremely curious and wanting to remember what it was for a long time. It was a pony game, I think it was cartoon-y but maybe not, and it was kind of difficult for me to play. I don't think it was super bright or sparkly. I remember you could feed the horse stuff, probably apples but I'm not sure. You could move the horse to other areas that were off-screen, and I think there was a locked/inaccessible fence?? I remember that it eventually stopped working for me, and I wasn't able to move or feed the horse anymore, so I stopped playing out of frustration.
I think it kind of looked like My Little Pony, but it was probably a ripoff. I remember the main area had green grass, and you could scroll back and forth, and if you went far enough to the right or left you wouldn't see the pony anymore.