Update for 7/24/2021

1. It is not allowed to generate Already owned items unless all items are owned.
2. Items participate in the calculation of gold coins now. The more items you eat, the more gold coins you get.
3. Adjusted the amount of getting gold coins.
4. In double player mode, when the number of tanks is greater than 0 (for example, eating a life item), another player can be revived.
5. Slightly reduce the enemy's bullet speed.
6. Greatly reduce the movement speed of enemy rockets to give players sufficient reaction time.
7. Player tanks are born invincible for a short time.
8. Fix the bug that the enemy tank has the probability of not moving at the birth point.