The way your synths cut in is a little obnoxious, just too much of a volume difference. It sounds like your attack and release on every single synth is 0. Are you just using presets without tweaking?
And is that FL Slayer?
I mean melodically its alright but its just like, thats all there is.
Try giving the lead some reverb or something. Also some drums would be nice
Its awesome! Nintendo needs to come on here and get some ideas for Awesome music!