Shoot trapezoids ... yeah.
What you do in the game is pretty simple; you roam around in this geometric 3-d rendered world and collect flags to progress into the next level. You either run away from these enemies or you can shoot them and kill them. You can jump with Y, X warps you randomly somewhere around the map in case of an emergency, A is your normal shot and B is your powerful shot. To heal or reload on ammo, you have to run over these green squares on the ground. Beyond the first few levels, you have to watch out for mines (red X's on the ground) and yellow lines (crossing one will result in a loss of one life). The number of enemies increase dramatically and they take a lot of bullets to kill. There are also warp gates of some sort on the ground which you can cross on to skip to different levels. Oh, if you miraculously manage to get another person to play, there is a 2-player mode too.
On to the sound and graphics ... they're really bad. I would have understood if it was on the Nintendo Famicom but come on, this is supposed to be a 16 bit game for crying out loud. The spaceships/tanks are just polygons. The bullets are just spheres of green and red. The sound is equally horrible; there's only one mediocre background music, there's an annoying chime that rings every time you get hit; and the voice over is really bad. It least it makes me laugh every time I hear the guy say "Tank Destroyed" and "Level Complete".
It's not so bad as to the point where I want to "gouge out my eyes" or "cut my ears off with a knife" but it truly IS a bad game. I wouldn't recommend it; just don't play it. You're better off playing Star Fox or something.