Yeah... I have to agree. The mastering just ruins what's otherwise a really good track. Catchy melodies, good buildup, pretty standard sound design but we can work with that, it sets a mood and stomps. The biggest non-mastering issue is that without any sidechaining, the kick has very little impact, and it's playing a 4x4 beat, so it needs all the impact it can get, but even with that, this is still some solid 4x4 whatever-step with some personality.
But this mastering needs to stop.
The highs are nails on a chalkboard. The human ear is more sensitive to higher frequencies, especially around 2-5k, so boosting them makes your track louder, but also literally painful (literally literally) to listen to for too long. You cut a lot of the lows to make room for the highs too, so instead of a wave of buttery-smooth bass music, it's closer to white noise. The overcompression only compounds the lack of sidechaining, pushing the kick further into the back and adding that trademark Newgrounds Sound (tm) that never, ever sounds good.
It's easy to see why lots of people like your music, you've got skill and you can put an original spin on a tired genre, which isn't easy. But I think a lot more people would give this a shot, or come back for more, if they didn't have to deal with constant ear fatigue from the mastering. Good luck