Ooo, very different from your normal style. Tinkering with the forbidden fruit of Chiptunes, I see.
I will start by saying this mix is pretty awesome and would probably have a good shot at the panel as it is. That being said, there are a few things that catch my ear that would could probably do better.
The overall mix tends to get cluttered. The drums overpower the other instruments a bit too much, imho, the textures dominate the themes and melodies, when there's counterpoint between the to themes (which is awesome, by the way) they fight for dominance, etc. It's not like the production is popping or anything, it's just that the song seems to lack focus, when it comes to the mixing.
The arrangement isn't bad, but it feels like it meanders a little bit before just saying 'fuck it' and fading out. Not sure if you can fix that in this mix, but having music that feels like it has a beginning, a center that drives to the end, and an end would give a remix a lot more direction. If you could do that with this mix that'd be awesome, but that's asking a bit much (especially since it doesn't take that much from the track, really), but it's something to consider for future tracks.
Mario coin sound? Wtf, but awesome
That's about it. While it's understandable to forego the arrangement issues I'm personally having, the mixing would be something that would be nice to fix. Good luck with the panel, when you sub this.