Ok this might be totally random but I think it might be possible to use the power of some GPUs to offload the heavy lifting. Imagine having a world with lots of stuff going on. It would be nice to have it offloaded to the GPU as the GPU can do calculations in parallel.
The source is available. Nothing stops you from starting to contribute.
Except my limited knowledge. 3D engines blow my mine let alone all the other complexities such as networking.
Minetest is amazing