Kinda goes to show how far they will go for peta to defend fictional creatures.
They're not defending fictional characters, but using it to illustrate a point of what the game might imply to young children. That is; The capture, collection, and fighting of animals with an apathetic attitude toward the total dominance and expectation of servitude placed on the captured animals.
It is a valid point, to some degree. I've always thought it was a shaky concept shrugged off by the cute and playful demeanor. Obviously Pokemon isn't reality, and children can determine for the most part reality from fiction if they have anywhere near a decent upbringing, however the sentiment holds true even in small regards.
I was 11 when the first Pokemon was released. I loved the game to death, and rightly so as a well designed communal game me and all of my friends would play. Pokemon certainly earns it's reputation as a classic and a cultural phenomenon. Now, while perhaps mild, it did influence my behavior a little. I did at one time capture and keep a bee as a pet like a 'pokemon'. The action was taken as a direct result of deciding that was the closest thing I'll get to having a pokemon in reality. It never went above an insect, certainly not like I was trapping mammals in the wild, or fighting dogs, but the sentiment was there never the less. I captured this insect against it's will, and held it captive in a container hoping to emulate what I saw in the game. The capture likely lead to it's death, and surely stripped it of it's freedom. It is exactly the point the PETA game is trying to make.
And that was a way more serious post than I thought it was going to be...