I can't figure out a way to hide potential spoilers from others who look at this page, so I'll have to leave some of my comments out. Overall, I like the premise of the game. The pacing is a bit uneven, though, with the ending in particular seeming more ambiguous than I think was intended because of that. (Even just rewording the last few lines or adding another line might help with that one.) There are also some typos that might need to be addressed, though I didn't think to write them down. (A lot of them were misused homophones rather than misspellings.)
The short play length made it hard to fully differentiate between the characters, but I don't know there's much that can be done there. I have some thoughts about the character who I feel got the most development, but it may be a bit too spoiler-heavy to write here.
As for the content listed in the warning, the level of detail does feel a bit gratuitous. However, that might well have been intended, as a sort of Corpse Party-esque guro. It makes me think of slasher films, so I think that sort of audience would be the best target audience.
While I mostly focused on pointing out negatives and opinion-based things, I think it was a solid game for the most part. Going into the game, I expected a sort of supernatural horror story but instead got a more sci-fi or even cosmic type of horror story. It feels kind of like a B-movie due to the limited character development and graphic gore, but it's the good sort of B-movie in that it's still interesting to play.
If you make versions past v1.00, I'd recommend maybe looking into some of the typos and the final few lines. Also, it might be a good idea to prompt the player to save as the final scene begins, to keep people from losing a lot of progress by not realizing you can save during the scene.
At any rate, I hope some of these comments help, or are at least interesting to read. If there's somewhere where I can comment about the game without potentially spoiling new players, I also have one or two specific things I might have some thoughts about.