This is an arcade-style game that can be played casually by just tapping the screen. Drop people who are about to be abducted by UFOs into a hole and rescue them. The people you rescue will be added to your collection as many as the quota. If you collect all 16 types of people, you will be able to solve the mystery of the missing black cat.
[About coins]
You will need one coin each time you drop a person from a UFO. You can receive coins by rescuing people, but be careful as the level increases, as the number of coins you receive decreases. Even if you run out of coins, you can still receive them by watching ads (20 at a time, no limit), so don't worry.