Because of environmental pollution and population surge, interstellar wars have been going on for hundreds of years. Come and find out the aliens hidden among us. Aliens of different races live on unknown planets. One of humans and aliens will surely perish. These aliens have special functions. They can imitate any human being seen, including appearance, character, behavior, etc. It is difficult to distinguish human beings. The war between different races has begun. Your task is to collect more amethysts and upgrade weapons and equipment.