Sopwith is a side scrolling shoot'em up created by David L. Clark of BMB Compuscience in 1984. It was originally written to run on the IBM PC under DOS but there was also a port made near the time of its creation for the Atari 520ST. The game involves piloting a Sopwith biplane, attempting to bomb enemy buildings while avoiding fire from enemy planes and various other obstacles.

Controls (they are crappy setup but let me test without taking hand off of keyboard for tests in Unity)
W / S: Pitch of airplane (how you make it do loops)
A / D: Throttle
Space: Machine gun
F: Bombs
E: Roll
R: Reset orientation back to neutral. Also costs 25 points to do this, so earn some points first.
G: Reset game

This version has some modifications over my old 'infinite runner' version. This is more true to the original game in that it has a limited level. It also allows the aircraft to roll for going the opposite direction on start.

Sopwith (itch) screenshots