Hi, this is just a personal oppinion, as im not a map judge or anything.
I got several stuff to say about your map.
1. The 'Rainbow' theme has been used SEVERAL times in maps, and its even recommended to avoid using as your theme in your builds.
2. The parkour itself looks way easier to be a medium map (again, just a personal opinion), when you choose the difficulty of a map, dont only just try to have the exact ammount of jumps, try to make t hem fit their difficulty.
3. The building itself its just a bunch of clouds and colored glass and glass panes floating, try to make something that you look at it and say "Damn, this guy took some effort to build it".
4. On this part over here, is kind of confusing where to go, as you already said in the signs "This is not going to work" you wouldn't expect the parkour to "Work" there, in my opinion you should've just removed the barriers and make more jumps.
As i said before, this is only a personal opinion, so dont feel bad if your builds get rejected, we all start from somewhere and one day we will forget where we came from, so, keep improving!