✅ As a result of the bullets, the enemy ship is destroyed and explodes.
✅ The enemies spawn time is random between range 0 .. 6.
✅ Remove any object from the list by removing any enemy or arrow from the game screen.
✅ In the start of the game, you have 3 ❤️ in left bottom corner that it show your remaining lives.
✅ Display player points in the lower right corner. Player score = number of enemies exploded.
✅ As each enemy reaches our planet, one life of player decrease.
✅ When the lives are over, the GAME OVER message is printed on screen.
✅ The speed of the enemy slowly increases.
✅ Sound is played when fired bullets or exploded enemy starcraft.
