Okay I know this is confusing so:
Hello Guest Prototype came first than the Hello Guest alpha 1 Hello neighbor 2 pre Alpha comes after it.
Was first called Hello Guest alpha 1 but than renamed to Hello Guest alpha 1 Hello neighbor 2 pre alpha, dumb Name if you ask me and confusing...
Hello Guest pre Alpha is according to Wiki a Trailer Build of Hello Guest Alpha 1, I am pretty sure you see this Build in the Announcement Trailer:
probably another Namechange, can happen a lot during Development. Alpha 1 seems to be more polished than Trailer version but Content appears to be the same.Is Unreleased so you should look for Fanremakes instead.