Forerunner to Forgotten Worlds. The control method allows you use the fire buttons to shoot in opposite directions, defending yourself from attacks from the rear. The power ups are selectable and if you collect an alpha symbol you combine with another ship for a super robot. It's not clear that the the name is Side Arms, as the US manual indicates the title is Sidearms. -http://www.pcengine.co.uk/HTMLGames/SideArms.htm