Ok, It can be downloaded from lewd.ninja, which I have no idea if it’s a sketchy website or not but here is the link: https://new.lewd.ninja/game/120942-slooter-v020-buxomdev-monsterbox

I’ve never known where you can get Hdoom but the offical download for Slooter can be found on Itch: buxomdev.itch.io/slooter

I’d link to a place where you can download the full version of Slooter for free but I’ve only ever seen it on a website that isn’t in the sidebar for this community, so I don’t know if I’m allowed to post it or not.