Many great works were created by accident. Sopwith is one of them. Once upon a time, there was a Canadian software company, called BMP Compuscience. It was developing database and networking software. It was its network software, Imaginet, which is the direct reason why Sopwith was created: the game, which supported multiplayer over the Imaginet network, served as a demo to show the network's capability. Ironically, the game has built up a strong following. The networking software did not.
Sopwith is a side-scrolling action game, where you fly a small plane. Your goal is to destroy all enemy buildings. To make your life miserable, however, there are a few enemy planes chasing you. In the multiplayer version, you could supposedly play with three more friends against four computer-controlled planes.
The game had several strong spots. First of all, it included a tutorial mode, which let you to play without enemy planes, in order to get used to the controls. Second, once you started to play against the computer-controlled planes, you realized that there's a pretty powerful A.I. standing against you. While the plane physics were skewed, the A.I. was pretty good at shooting down the human players. Lastly, the game featured a really catchy melody, which I caught myself whistling long after I finished it.
On the other hand, a few negative aspects have greatly devalued the game. Maybe the biggest problem was that the game offered only one level and simply dumped you back into MS-DOS when you finished it. In addition, the fact that there was a strong A.I. and only one level meant a very steep learning curve. I remember almost breaking my 8086 out of frustration. Lastly, there was no way to turn off that annoying plane sound.
Overall, however, I think that this game can be credited as the first graphic multiplayer game. It came way before its time, yet, unlike many other games, remained with us until today. To play it, however, you need a slowdown utility, as the game can be a little fast on today's computers, which are roughly 400-500 times faster than the computer it was written for.