Trade this game in for Zero Mission.
The graphics are obsolete compared to the newer metroid games, and there are so many glitches (But all metroid games have a lot of glitches) and there's only 3 bosses, but this was a time where games were only a few levels and were very hard too.
Now I'm not saying that metroid is a bad game, but compared to the game boy advance remake Zero Mission, it's nothing. It's a good game, but since this was included in zero mission, this is just throwing your money away.
So overall, if you own this, just trade it for zero mission and if you can, also get your hands on fusion. They're both really good games.