Highly recommand, I too was skeptical when I first saw this concept of a Killing Game where only one person needs to die I just felt like it would be a short adventure with maybe a few endings to explore and maybe also a true one for funsies...
But it's a lot more than that, a lot of mysteries, a story way longer than I could ever imagine, and oh my god the game's art, music, and even THE UIs are so good, like it's probably the most polished visual novel I've ever played :p
Also the game is super well paced, you'll never get bored. The immersion is really good too.
I get that the game may seem a bit pricy, but the final product's quality is so good that i feel like it's a fine price.

