Steel Empire is a fairly decent shooter with good graphics and passable sound. I like the fact that they got a little creative and made a shooter where you're not yet another spaceship blasting alien invaders--the retro mechanical flying ship/zeppelin idea was pretty imaginative. You can choose to control either a big zeppelin or a little biplane. The zeppelin takes more damage but is slower. The biplane is weaker but faster and more maneuverable.
What stops Steel Empire from being better are both gameplay and design issues. The level design can be a bit boring and the game suffers from slowdown when a lot of enemies appear on-screen.
There are better shumps available for the Genesis and then there are worse. Steel Empire is definitely middle ground.