Players must defend themselves from aliens, which assault them every wave. Defenders will get money and experience for killing aliens. With new wave, count of aliens raises and boss appears every fifth wave, he is strong, but his killer can get a lot of money and experience for killing him. Players can spend money on different guns and randomboxes (crates, which open for money and give you some item), so experience is a point which determines when player will get a new level. Every level up player gets one statpoint, so he can improve his stats - mobility, shooting, survivability and magic. For completing simple quests player will get different stuff like helmet, longjump, etc.