to get 3 stars on lvl 1, try to shoot down the enemies base as fast as possible under 500points(but dont destroy it). you will get one big enemy wave at 1000hp and another one at 500hp. after killing those two waves just kill enemy ships until your score rate is 0.1. Don't forget to set max skill to your base health.
 "Black Navy War"){kind=icon}
 "Exploit"){kind=icon}
 "Virtual Drums V2.0"){kind=icon}
 "Rollercoaster Creator"){kind=icon}
 "Hot Girls Dating"){kind=icon}
 "River Defense"){kind=icon}
 "FWG Bridge"){kind=icon}