Within Unlimited SaGa contains an intutive 'Ecology System' in which the entire ecosystem of the Unlimited SaGa world is affected by the ecosystem in the game. Such as how other races are effected by lack of a cetain creature or food. Reducing the Slime population for example reduce the amount of water in the world; thus, the Aquan population will drop dramatically. However, since Aquans feed on Insects and Undeads, there will be more Insects and Undeads as a result. The effect of this system can be seen in different regions however.