Hello connortheguide,
Unfortunately, I will be
Rejecting your map.
The theme isn't very original, as there are multiple undertale themed maps already, however there aren't any exactly like this. Please refer to the document in this thread -
https://manacube.com/threads/parkour-list-with-theme.20194/ to make sure your map idea is original.
The build isn't great, it's quite messy. In the future, try to have one or two main builds as your map, then implement the parkour into that, rather than having many floaty islands with parkour on them. I also noticed a lot of the builds are pixel art. Try to not have pixel art as your main build, as unfortunately, pixel art based maps are no longer accepted.
The parkour has a bit of variety, however there were quite a few repetitive sections. You would have long sequences of just normal blocks, then just glass panes etc. Try to mix up your jumps a bit more throughout your map, as well as experimenting with a larger variety of blocks and items when building parkour, as this will make your map more enjoyable to complete.
A lot of the parkour is floating. I do understand that this is inevitable with the nature of the build. But as I previously mentioned, try to have one or two main builds in your map, then implement the parkour into that, as having an excessive number of blocks floating around your builds can make your map look a bit messy.
The difficulty is good for an easy/medium map, but the length is far too 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.