Hello xInitial,
Unfortunately, I will be
Rejecting your map.
The theme isn't very original, as there is already a slime related map (
SlimePK - Expert)
The build isn't great, as it's mainly just a box with slime at the bottom, in the future, I would suggest trying to make a main build that has a bit more shape to it, that is relevant to your theme, as this will make your map more interesting. I do like the idea though that navigating through the jumps in the inside with the slime gives it a bit more challenge.
The parkour is very repetitive, as it's mainly normal blocks and slime jumps. Try to experiment with a larger variety of blocks and items when building maps, as this will overall make your map more enjoyable to complete.
The difficulty is good for an easy map, but the map is a bit long. Please read over this thread -
https://manacube.com/threads/must-read-map-submission-information-format.649/ to make sure your map fits within the requirements.
Thanks for submitting your map! I hope to see more maps from you in the future.