It wasn't ever released for PC. I know that since I was also interested in reviewing R-Type several years ago, after I saw it works in DOS. But that was only because it has emulator of arcade machines implemented.
There are also games for certain japanese consoles that can now run on PC machines. This was also done by fans, but I'm not sure is it actually an emulation.
Either way, those are not the games that were actually released for PC, therefore they won't appear on abandonia. Just because some game can now run on PC machines doesn't qualify it for our site. Perhaps some of them can appear on Reloaded, I'm not sure, but current Abandonia policy is to host only the games that were commercially published for PC computers or very old DOS freeware games. Check it again and correct me if I'm wrong, but I don't think that R-Type falls in either of those groups.
And welcome back. You wrote several reviews very fast and you were away for a while. Actually, I was away too, so maybe I just didn't saw you