I have a gold ball with solid and and bullet movement with angle toward mouse x, y. A silver ball with the same behaviors and
System - start layout - system create object (random (1, 360) random (1, 360)
Enemy - bullet angle of motion to random (1, 360) degrees.
At game start, both balls bounce off walls normally. Silver ball changes direction when hit by gold ball the first time but after that the silver ball will not change direction when hit again.