Thanks for the kind words, and the feedback. It was absolutely a passion project for me, and I had a lot of fun writing Batty's character and coming up with the scenario.
The sequel is currently in development, and releasing this December (check out battyzabella.com if you don't already know about it). I really hope people enjoy playing it as much as I'm enjoying developing it. As a creator, if I'm not having fun making something then I see no point to do it.
As for a standalone version of the minigame, it is something I've considered, so it might happen eventually. There's a bit of history to the existence of that "secret arcade" in the first place, so I may one day also do a video or something talking about it.