It looks great, the parkour is super fun and varied +1. The only thing I could suggest to make the map even slightly better would be more block variation to the horse itself, but even without the extra block variation I am 95% sure this map is going to be accepted.
I'm going to be giving this map a -1 for the following reasons. There seems to be no main build itself. The parkour is mostly floating with a little stone tower in the middle. The parkour is mostly floating (as I already mentioned) and there is hardly any variety. What I recommend is using...
Rainbow_Llamaaa
Shark
It's in the second plot, but int the back. Go to /plot v Rainbow_Llamaa 3 then just turn around
About 20 jumps with 2 checkpoints
This was rejected a while ago, because there was other "fast food" maps. Then subway got accepted, so I decided to tweak taco bell and resubmit it.
Rainbow_Llamaaa
Taco Bell
/plot v Rainbow_Llamaaa 2
about 38 jumps and 2 checkpoints
As the other 2 mentioned. Floating islands is the most overused theme in the entire server, and that makes your chances of acceptance close to none. Either way, good luck.