"This is definitely one of the densest pieces I've written and I was actually worried that the mix was a little too full"
You'd be right, sir. And in fact, I love that kind of density.
It feels pretty tight in terms of mastering, I have to admit, and it doesn't really give much breathing space between the various instruments, but guess what: this may be one of those exceptions. It works in that the atmosphere you've created here strives for neither realism nor compositional complexity.
It works very well in a video game, as many people have noted before, because there are many elements in the song reminding them back of that glorious golden age, the chiptune era of video games. Might be the lead synths made of simple waveforms, might be the relatively uplifting mood, might be many things.
The only reason I'm not giving this full stars is because that realm belongs to those tracks that manage to go beyond the vision and create something extraordinary, able to compete with the professional world and beyond. This is, however, already a great start and I can only encourage you to pursue this way. There's nothing really faulty in my eyes in terms of composition, choice of instruments, atmosphere and the harmonic context this track is permeated with. That's mere taste, and with that said, I shall return to my slumber knowing there's great music and great minds around.
//FD