Very nice entry, a bit confusing and twitchy for me.
The music and pixel art are great, and most probably the sound effects as well, but it was hard to hear them over the music.
The whole game was a bit too fast paced for me, and I couldn't get the rhytm of the jumping down, so I ended up mashing the spacebar during the whole duration.
The pickup effects were nice and juicy, loved the rising pitch on fruit collection and especially the effects on collecting a gem, with the distortion and the timestop.
I think it would be great to not just stop jumping if you don't get a combo, but to always bounce by default with a tiny jump height, and get more height as you build your combo up. Also, when you're in a combo, and can jump again, It would be nice to have a few freezed frames to have a greater window of time to make a jump input. That might also give jumping a bit more impact and satisfaction.