Just as the title says, I want something that makes everyone forced into a cruel game and turn on their survival instincts. I'd like it if there isn't any romance or harem, but BL/yaoi is an exception. I have read: Earth is Online Omniscient Reader’s Viewpoint
The Earth Online (similar name, no yaoi, kingdom building, lots of trashy second gen rich kids, mc loyal to the girl he likes) Angel in Online (tl dropped but kind of a death game, you die in vr, you die irl)
Yo, this pretty much fits your criteria although there's no Kingdom Building in it's Genre. *Reincarnator from Gravity Tales
Escape the Infinite Chamber and Kaleidoscope of Death (this one is quite gory but great). Welcome to the Nightmare Game also should fit your taste, although I'm not sure as I didn't read it.
game loading is pretty good it has, as the name states, game elements and has people kind of playing for their lives in various 'games'. it's also bl and super well written in my opinion
I'm Not Shouldering This Blame has a really similar vibe, but not really plot wise. They're both among my favorites.