ecktronic - I agree with Farview's comments ... you can hear the sound of the compression distinctly and the high end is very sharp and over-defined. But it is obvious that the recording was well done .......
with that in mind, no offense is intended here ... but I feel the need to say some stuff about stuff eventhough I'm not qualified to say much about anything
I don't know if you're being paid for this mastering or not ... (I will go ahead and assume you are, and I think this goes out to anyone else being paid to master music). This project you have here is a classic case of why mastering isn't proper unless you actually have the right chops/gear/know-how - Mastering might not be an island in the middle of a choppy sea, but the way there is still treacherous - one wrong move and you're sunk! Of course, I am not saying "give up on mastering, it's hopeless", but definitely consider the consequences of mastering someone's material when you are not a qualified mastering engineer ... or at the very least, if you are not a qualified mastering engineer, be very up-front with your clients so that they don't expect miracles.
It would be like me charging people to record and mix their music when I know that I am not a qualified mixing engineer nor do I have all the right material and know how to be a recording engineer -- of course, it doesn't stop me from recording and mixing my own music and reading about mixing and mastering ... or actually mastering it if I want to (because I can do it without much, if any repercussions other than "oh I'd better go fix some stuff in the mix".
Now if you are doing this on your own material for kicks, or are just trying to learn more about mastering, then it's all good - do what makes you happy -
Peace
R