omgad, i have a fan!
Welp, I don't buy into the whole minor/major thing. I suppose I use them as a base and modulate/create accidentals when necessary. For instance, that chiptune you like (Spitting Fire, I am assuming) is written in a minor key, but it doesn't have a "sad" feeling. Keys are just are just aesthetically guaranteed sets of intervals. Sure, people will tell you there's a happy/major or minor/sad quality to certain keys or intervals, but it's all in the context. If you're writing in minor keys and all your tunes sound sad, then that's either your intent or you aren't being creative enough with how you're using that scale, accidentals, or harmonies.
And yeah, chiptunes are definitely awesome <3<3