In the menu which is located on the right you can purchase towers. The top is the menu already-established turrets, it demonstrates characteristics: damage, distance attack and firing frequency. Choose a tower on field and click on her then specify what its characteristics should be improved.
In the main menu in the "War-Mart", you can buy various global improvement.
For each enemy killed you earn money that can be spent on purchasing new equipment and improve it.
Each weapon has its own radius.
