Purchased the steam version a few years ago, which has been unfortunately delisted from steam afterwards. The latest steam version is 2.04 and there has been no updates since then. Someone asked wolfzq about this on patreon and he seemingly refused to provide newer versions to steam owners, instead asked them to purchase another copy from other store. This is a shame.
I'm not blaming the dev for trying to make more money with his work, but this is an RPGMaker doujin game anyway. He's already charging people like $70+ for costume DLCs, but can't give old owners the latest version which they deserve. Sigh. I'll not pay another cent to the dev for his future games until he hopefully come up with a better understanding of how to do fair business.