@Avi1140 vndb lists the main game (these 6 sets are from extras/side stories) with the tag "Bad endings with story" and does not have the "Only bad endings" tag, so most likely it does have Happy endings and Corruption endings.
On an unrelated note, this is the first time I've seen tentacles ejaculate into someone's nostrils (CG 19). The world of tentacle hentai is vast.