Hi Korikabu,
Thanks for writing in! The game is considered complete. It received its final update, which is v.1.04, on June 7th last year.
The supposedly v.1.05 update snowballed into massive changes and huge improvements that make the game feel different. It will be a completely new game (think of it as a version 2 or a remastered version), but there's no official name for it yet. It's been in development for about 9 months now, and it's nearing completion.
Once that new game is released, owners of this game will receive a free copy of it.