There are various worlds available that you can travel to in order to fight endless waves of enemies. Each world is set in a different kind of environment where different waves of enemies are at home. In order to get access to a world you have to purchase access in the shop. Only the greenland world is available from start.
Your home world is the basis. This is basically your home set in a mysterious dimension.
The following worlds are currently available for access
|A very fruitful green world occupied by a military force
|A cold, freezing place inhabited by various alien monsters
|A desert-like world occupied by a military robot force
|This very hot and infernal world is inhabited by an alien force that are building motherships
|This world is inhabited by an alien species that evolved to live under water