There are 2 parts in the game, math and shooting.

User have to solve the math in math game, then, you get the coins as rewards.
Then you can buy some weapons using coins you got previously.
Finally user play shooting game.

1. Select slot, if it's empty you have to type nick name.
2. Select difficulty and math operators you want to solve.
3. When asteroid is spawned, there is a math question on it.
4. Type answer number then touch fire button.
5. If you earn enough coins to buy weapons, and if you want to buy it, buy it.
6. Some times, you need to select attach a weapon on left side or right side.
7. Play shooting game.

It's Free app and NO ads. :)

Acknowledgements

My son, Dohyun (8 years old) drew a spaceship for me. I'd like to say thanks to my son. :)