This is fun! I love all the little references to all sorts of themes. I chuckled for sure hearing Africa.
I feel like a lot of the midi tracks still kind of have that flat, unfinished virtual instrument feel that can be hard to escape sometimes if you don't manage it. I.e. this is something that can happen when each note sounds exactly the same right before the next note, it throws off the sense of articulation which can make it feel a little flat and dead.
And, even if you're doing something humorous and "midiesque," this still matters, and a lot of instruments and compositions for video game music ironically actually have a lot in common with Baroque music to deal with similar limitations. I.e. the Super Mario theme gets around the repeated note thing by being super staccato and using varying "percussion" noises:
I.e. even despite the significant limitations here, the theme song is super pleasant to listen to regardless, like the right sounds being chosen in the right places to manage the deadening of sound that you get with sounds that have no volume variability or room for any sort of articulation. The percussion creates the illusion of articulation.
Adjusting things like length of time for notes can help with this too. People use midi controllers too to get around this.
Overall though, this is impressive and is an impressive output of very creative work. My detailed explanation above is just trying to be specific and concise about what I mean. You've done incredible work here.