I noticed that too while I was trying to dig it up to download a fresh copy. As it is, anyone who bought it can't (re)download it, which is a little concerning.
Hopefully that page gets reinstated soon, or something.
Viewing post in Battle Century G Remastered comments
Fixed, sorry for the inconvenience. I think it got restricted accidentally during yesterday's update. My best guess is that the default visibility settings change the project to restricted when editing it, which has never been a problem before, but I might have missed it this time? I'll be keeping an eye out from now on. Thanks for pointing it out!
Which, um, by the way, there's a (minor) update for BCS! Go get it before an internet gremlin takes it away again.