I would EQ the top end of that fade in string sound by a few db, it's a little harsh on the highs. Same with the tambourine. It's just a little sharp. If there is a reverb on the bass guitar, I'd consider removing it, maybe EQ it up a little for warmth and depth. Kick seems to have reverb on it as well, would sound better if it came through a bit harder. A nice warm snare would do wonders in many of the parts. Love the acoustic guitar. I wish I could play guitar, I'd love to have acoustic sounds like that in parts of my tracks. Last thought, maybe add a little compression after turning up the kick and thickening the bass.
Reminds me of some anime intros, hehe. I like the guitar and the synth mix, but I think it would be even more rad to add the vocals.
I am not used to listening to instrumentals, just my thought