Twin Hawk is an airplane shooter, you're flying over wasted land filled with tanks. You're shooting, and being shot by, everything that moves. In concept, the game is strangely similar to Flying Shark.
You start off with a double shot, and very spaced apart are the (P) pickups that lets you earn a 4-shot and then a 6-shot.
You start each life with 2 helper groups, once they're used up you have to rely on skill to get anywhere. To access the smartbombs, just press the helper button twice, this will cost you a helper group though.
The helper groups are a bunch of airplanes that are equipped like you start, with doubleshots, and when you shoot, they shoot. This is great for certain sections of the game with very intense enemy waves and your friends are great shields too, no need to dodge as often, just hide behind a helper airplane and that plane will go down instead of you. If you press the helper button again, the helper planes kamikaze to take out enemies. To get a smart bomb you must press the helper button two times quickly.
A difference from most other World War 2 Shoot'em-ups is that all the enemies are ground targets, you don't battle any airplanes in this game.
The game was converted to PCE and SEGA Genesis. On the Genesis, the sprites weren't scaled down (at least not very much) so what you saw was about 1/2 the arcade screen. It made the game a bit more visually impressive, but it was trickier to play.
The game was released on both HuCard and CD for PCE, where the CD version is called "Daisen Pu Custom" and had added levels, music and enemies.