Let's sse...
Your cymbals are a bit... misplaced. In fact, your percussion in general needs work. I suppose it's alright for an RPG Maker game, a dungeon in particular, but it gets kinda boring, especially if you were to hear it in-game repeated over and over. It also sounds empty, which is almost fitting for a dungeon, but I'm sure that was just coincidental the way it turned out. Still, it needs something more on the bass end... a tuba would probably fit well. Also, your timpani are out of range, lol, which I'm sure doesn't matter to you, since it's just some random song, but just so you know.
The melody is alright, but it could use some harmony...
You're off to a good start, but don't stop now! There are still imporvements that can be made, just take it a little bit at a time.