Absolutely nailed the voicings that games of that era use; from the heavy vibrato, the fast-decaying and arpeggiated chords to the creative use of noise bursts, swishes and percussion stand-ins. I can absolutely envision hearing this in a game from back then. I love how you've captured the flair that this era was known for with the little trailaway arpeggios and catchy but brief Stage/Level Complete jingles.
Great work, chiptune is such a rewarding genre and those who know it well can really produce some great sounding stuff. Best of luck!