I'm so sorry if this is annoying based on how long ago this comment was, but nobody else felt the need to correct you. Skip to the last paragraph if you don't want a full explanation of what this is.
Basically, Gacha Club is NOT available finished on PC. only the demo (last time I checked), which doesn't let you do as much. Feel free to correct me if he added the finished version to his itch. This is called a Gacha mod, which PC users typically go to. For android users, its completely optional.
Gacha mods are just the original games with items, backgrounds, accessories, and etc. added for more variety of items. From what I can see, they did add things. If they didn't add anything, and claimed it was their own, then THAT is claiming Gacha Club is their own game with just a different name.
Please realize this team of people is just trying to make their own version, and Luni is COMPLETELY fine with it! They also added "MOD" in the description of their game, so they are NOT claiming this is fully theirs! This is Gacha World, not Gacha Club. Gacha Club is Lunime's, and technically so is Gacha World, but the new things credits go to everyone credited in the description! Thank you for taking the time to read.