this is the prequel, not the "full game"; I'm pretty sure.
This one is more like a "what if" that he made with scenes that he didn't get to use in the other game but decided to rework them a little bit, put some extra dialogue and stuff and ship it, the one I shared is the full game where there are two other chicks who also get corrupted and NTR'd and the mother also gets corrupted by bugs in a similar way but it's a bit shorter
Dazedanon only shared this one he translated, the full game has a commissioned translation paid by the dev himself, i know it because i bought it a while ago and it's not MTL