I hear that the mass of the universe consists of 90% Dark Matter which I believe is a very heavy substance which cold be with much work implemented into the game, Dark Matter refers to matter particles, of unknown composition, that do not emit or reflect enough electromagnetic radiation (light) to be detected directly, but whose presence may be inferred from gravitational effects on visible matter such as stars and galaxies.
I am not all to sure of objects that Dark Matter can form but seems to be an idea to pounce on make it a little more exciting. just a though what do other here think?