Enemies

Stone in space. Flies across the screen from a random location in a random direction at a random speed.
When colliding with a player or an asteroid, it is destroyed.

Moves at minimum speed. Shoots in 4 directions diagonally 2-5 times per second. When the player approaches, it is destroyed without leaving any points.

It moves across the screen not only from top to bottom, but also left and right across the entire width of the screen. Flies out in groups of 10. Shoots forward 2-5 times per second.