Hello ThatGuy354,
Unfortunately I'm going to be Rejecting your map.
The theme isn't very original considering there are already maps based off of large blocks (Megablocks - insane for example)
The build is very plain, I know for the theme, you built single blocks, but using 1 block for each colour in a larger scale makes the build look less attractive to look at, I would reccomend using a variety of blocks to add more detail.
The parkour isn't that good, mainly consisting of single blocks & ladders, I would suggest using a wider variety of blocks and items in your jumps to make them more enjoyable to do, and to make the map more interesting. I was also concerned about the number of barriers used, I would suggest cutting down on the barriers, and also adding something like item frames along them, to show where they are to make it less confusing when doing the parkour.
The parkour was also too easy for an expert map.
Thanks for submitting your map! Hope to see more maps from you in the future.