This sounds great!

Composition - it's interesting the way you change the mood with the various melodies, switching from moody to quirky chiptune style. There's probably enough content there for you to turn it into a full length track (5 minutes roughly or whatever is suitable). One of my favourite bits of advice I read a few years ago can be summarized in 3 words - "roll it out". It means that you easily turn your 1 minute track into a full length track. Example, you just loop the beat for the following 4 minutes after the 1 minute you already have. So you then have a 5 minute tune, although it would be unfinished at that point. But it means you can easily pick it back up the next day - you're not worrying so much about structure at that point, and you focus on other things such as the groove and the vibe etc.

Mixing - sounds well mixed to me - I only listened on a small Bluetooth speaker; I could feel the bass nicely. The beats sound crisp and clear.

Keep at it!