Big Sky Troopers for SNES?

Has anyone ever beaten this game? I've made it incredibly far, but there is this point at which it seems it is impossible to advance. Is this just a common characteristic of many SNES games? There is some glitch that makes them completely unbeatable? I mean, I really worked on this game up until I was about 11, and then I became frustrated and put it away for a number of years. Well, its been about 10, and I really want to finish this game. Please, just let me know if it is even possible so I can sleep at night.