You can move around one cell at a time. Explore the world. With every move you earn experience. The number of experience points depends on the type of ground of the cell where you stand. Some cells give you lots of experience, other give none.
If you find yourself on the same cell with another monster, there will be a fight. Either you will kill him or he will kill you. Only one will survive.
There is no pause in the game. If you leave, someone may come and eat you. Make sure to build a shelter before you leave to stay safe.