>>1541441Morimiya Middle School Shooting
It's very niche, but as the title implies, it's a game with the premise of shooting up a middle school, that includes schoolmates, staff, and cops.
It takes place in an alt history version of Japan where gun rights is the same as in the USA, so you also have the NRA and stuff in Japan. It's more of an excuse for the plot to work. The protag is given the backstory of dad leaving her and mom comitting suicide, so she's all alone and depressed.
The premise is very taboo but the way some people treat it is like some forbidden media. Your mileage may vary especially if you're American, but it feels like it's more controversial due to how the topic rarely gets tackled in a video game. The actual execution isn't too far off from the violence you can already enact with the likes of Postal and Hatred, and some might argue it's a little less brutal visually since it is presented in a chibi RPGMaker style look.
It's also highlighted for pretty much pushing RPGMaker, creating a shooter with some realistic elements that isn't just run and gun.