Assets from all versions of https://www.dlsite.com/maniax/work/=/product_id/RJ01258175.html - The free edition (obtainable on the author's Google Drive) - The paid edition (See the DLsite link above) - The celebratory one which was available on ci-en for 24h, a few days ago
Art wise a very simple game but if you are a fan of mind control/brainwashing/corruption/identity death then this is a must play. Honestly the setting is so simple but so effective with this writer and even this artist that I wish this would just turn into a whole series of games. Btw I know it's based on the Neptune games/Anime whatever but I never saw/played them but I don't think that's really necessary to enjoy this as well. You might enjoy it even more if you are familiar with them though.
I Can also recommend this game, it's very creative and manages to use the small size to fit a lot of content. It's a game i find myself returning multiple times to check again. I have zero clue about Nepture games and enjoyed this a lot. The game has multiple endings based on your actions, it's not a hard game on itself, but most of the difficulty is finding how to get through some puzzles. there's very limited fighting, and no need to grind multiple times for levels or power-ups.