One thing people forget about the sixteen bit wars is that it was hard fought and Sega did give Nintendo a run for its money. The main reason, it had a faster processor. You cannot dismiss speed as far as helping a video game move along without slow down or flicker. Nintendo ultimately won, but the victory was achieved most likely due to RPG games as the Super Nintendo had a plethora of them. Which is sad, as the Genesis or Mega Drive could do a good RPG as Phantasy Star IV was as good as many of the best stuff on the system. As for a game like this, a vertically scrolling shooter, the system was designed for games like these!
The story, I am not sure, I did not have the instruction booklet; however, from playing it and seeing the missions, it involved some sort of evil army most likely run by machines trying to take over earth. You must pilot your Mech robot through several stages as you repel the enemy forces, blow up their bases and defeat the evil computer in charge of it all! You know, typical shoot em up type stuff.
The game play is what one expects, very frenetic with enemies and enemy fire taking over the screen. On your side is your robot who can power up. While wielding a secondary weapon you can take a hit and not die, but if you get hit without a secondary power up shot, you lose a life! You also collect this icons that when you get enough you can get two ships to encircle your ship and provide more firepower and they can also be a shield too.
So, pretty typical of a shooter from back in the day, but it is a lot of fun. It was a bit difficult for me; however, I am not the best shoot em up player, from what I hear this one is quite easy compared to other shooters out there. The graphics are good, very little slow down even when the screen is swarming with enemies. Kind of wish it would slow down at some points so I can read the screen. Still, it is fun and I recommend giving it a try, though the best way these days may be an emulator as most physical copies are really expensive.