Seriously,how a game with this low end grapighs can lag a PC that runs battlefield 1 on medium grapighs?
All of that is, frankly, a trivial O(N) problem with some glitzy graphics thrown on top. The CPU load, like most FPS games, is trivial: it's all the shiny effects that slow you down because of all the scene rendering the GPU has to do.
On the server side:
Each physics frame, a bullet can ask "in any of the grid cubes I passed through, do any objects have colliders? If so, did I hit them?". This is constant-time per bullet, since it only has to poll nearby objects, and O(N) in the numbe