I'm a fan of chillstep. I like how things sound "almost" hectic in a mix haha.
I like the feel you present in the beginning and slowly introduce more drums and your lead. However I feel more production could be added. Maybe a second lead to follow your main one?
Also I would recommend trying to add different chord changes instead of the same 4 chords on the piano, you do add a few small riffs, but I feel you should expand your creativity, in fact I encourage it. Add various movement to keep your listeners interested!
You got a good sense of melody and rhythm and I was definitely chilled listening to this. Keep it up!