About the most unique thing you can say about Zed Blade is that it was one of the few Neo Geo MVS (arcade system) games never released in cartridge for for the home (AES) console system. It's a meh-y shooter that just seems like a watered-down version of later hit (and source of the Fail meme) Blazing Star.
The game has you choose from three odd and military-looking characters. Each has their own ship, but you get to choose your own weapon layout in Gradius style - front guns, rear guns and missiles. Then it's off to eight levels of fairly generic spaceship blasting, which begin slow in pace and easy for the first couple, but later on pick up and become a pretty fiendish challenge.
Early enemy ships fly in with a sort of low-grade 3D effect as they transition from polygons to 2D sprites, but don't lead this to make you expect 2D/3D hybrid goodness on the order of Border Down, or even the fairly simple tricks used to spice up Blazing Star. All you get is the occasional 3D effect meshed into an enemy 2D sprite, with some bosses on the caliber of 3D stuff done on the Sega Genesis around this time in games like Vectorman and Gunstar Heroes.
Unless you're a really hardcore sh'mup fan looking to suss out every possible shooter ever made that is even halfway decent, there's no reason to bother with this one. It's fundamentally not that bad, but it's far from greatness as well. The soundtrack is bland and kinda annoying, the boss battles are "meh", and the difficulty just kinda jags from too easy to cheap about halfway through the game. Nothing else is really remarkable.
* Gameplay Video