Computer Christmas Card

Virgin released a Computer Christmas Card that, as the cover states, included a free shooter called Ambush.

Ambush is played on a single screen with no scrolling. You can move your vessel all over the screen, shooting at enemies or avoiding collision with them. Enemies enter the screen from the top and move at various directions and speeds toward the bottom (they bounce and change direction when hitting the left or right side of the screen). When hitting one of them they split into smaller ones, which may have a changed direction and movement speed (this is repeated for the first and sometimes for the second hit).