More like this...
In Circle's war you shoot at incoming balls until they are destroyed. If one ball touches you the game is over.
User - white centered ball
Enemies - the other balls that can come from any direction and may have different size
Bullets - don't worry you have infinity bullets, make sure your shoot direction is correspondent enemies place and kill they by clicking mouse
The game will become a more harder and faster.
Good luck. Protect yourself from enemies.