Still no MAIL
But to go on with the gravity thing.
Its not size that matters but mass. It depends on how heavy oddworld is. Earth has a crust a mantle and a core.
the crust is made up of just rock, the mantle is made of molten rock (wich is a lot denser and thus heavyer then the normal rock of the crust) and a solid iron core wich is denser then the rock or molten rock.
If odd world dousent have an iron core the waight would already be substancialy reduced and thus the gravity is reduced too.
This alone probably won't do the trick but there are other factors at play. Like the many moons of oddworld who pull at it surfase, the spinn of the planet, other factors canceling out gravety like the above sugested spooce and the logikal adaptation of life to the gravity of oddworld
