I Have a Mission System in Doomsday

On Blue Star, alien-like monsters suddenly invaded. They are almost invulnerable. Only rifles and above can cause some damage, and their numbers are very large. It dealt a huge blow to Blue Star at the beginning of the login. The protagonist also obtains a mission system before the monster comes, and can exchange mission rewards for various technologies and equipment to strengthen himself. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.