Experiment B is a Minecraft server that tries to recreate the full Backrooms lore in-game. You start off in a harsh, creepy world where entities are always a threat, and staying alive is half the battle. The whole thing is built around exploring the backrooms, surviving the conditions, and pushing deeper into the different levels.
You can explore procedurally generated levels like 0, 1, and 2, with 18 levels available at the last update. Mine blocks, gather resources, and build bases inside custom-made environments instead of a normal overworld. There are also custom items and blocks to discover, including gear and tools with special effects like exploding enemies on hit or placing a portal to another level.
The server also has factions, so you can group up with other players, build a base, and try to become the strongest faction around. On top of that, there are NPC factions, missions, and a way to sell items and work your way up while exploring more of the Backrooms. If you like fighting entities, base building, and a weird lore-heavy survival setup, this is pretty much what it is.