In 1984 a great shoot em up was released for the Arcade by Capcom and that game was 1942. A game in which you shot down enemy planes, avoided being shot out of the sky and performed awesome rolls while collecting power ups. One of the more unusual power ups was being escorted by two other planes in formation that gave you the edge. It was an awesome game and still is today, but thanks to a mention by Zsolt there's a new shoot em up that's appeared on Steam Greenlight that's inspired by that great 1942 game. It's Knights of the Air, a top down 2D/3D shoot em up set into the first world war.