Gorilla Games actually. But yeah, according to their website, it is a chain from what I can see. Only 5 stores (2 of them in Melbourne), so it is a bit of a small chain however.
Now, I'm not 100%, but if I had to guess, I think it's a fairly new chain. Seeing how there's very few stores, and while my memory isn't the best, I don't recall seeing one the last time I was in Melbourne before this year (about two years ago).