I'm not on VNDB (I barely use it) but I'd just like to say I like this idea.
Meanwhile, here's what limited knowledge I have about DRM on VNs, for anyone else interested in this:
- anything from GOG, JAST, or MangaGamer: DRM-free
- anything from itch: probably DRM-free. (I guess devs could include their own DRM but I haven't ever seen it done, except in a few cases where all they do is sell Steam keys and no actual downloads from itch.)
- anything from Steam: a crapshoot, really. or worse, if you consider the fact that you can't download an installer. You may be able to ask around to find out whether the game files will run without Steam, but someone might accuse you of being a pirate if you do that.
- anything from DLsite: the store page does say whether it uses certain forms of DRM, but I don't know if system region setting requirements (e.g. only works on PCs with region set to Japan, beyond just encoding issues) are accounted for on the store pages.