Really cool song you have here. I think it would do great in a flash game or movie.
And your intention was to make a dungeon stylish, but like you said it came out different. What i imagine when i hear this is the part of a movie where the bad guys are preparing for doing.. well, bad things :P
But let's listen a little closer to this song now.
I really like the intro. It creates such an ominous mood. The little pizzicato strings draw your attention while the bass is a very solid foundation and then more synths enter the song. The strings are on a brilliant in the mix and the piano that comes in so pretty and dark. It's one of those things that creates the ominous mood i was talking about.
The arp that comes in just before the drums is done very well and.. i love that low bassdrum just before the other drums come in. Great use of dynamics too btw.
The drums itself are really attention demanding, but not too much.
I really like how the drums just stop for some time and give you some time to breathe before it continues.
But i think that the piano should be a bit more noticable. Just a bit, not too much.
Also, i think there could be a bit more variation in this song. I'm not sure about that though, because when you play a game or watch a movie the music shouldn't draw too much attention. So yeah, it's perfect right now :P
I have only one more thing to say. If you want that this song gets used in a game you should let it loop. You didn't create this to loop though, so i won't take that with me when i give your song a score. And giving you your score is exactly what's the only left to do. Great job on this song!