Hello Quazjinx,
I am sorry to tell you this map is being rejected. The theme is slightly unoriginal, since we don't have any ukelele maps specifically, but we have many instrument themed maps, including a Guitar map. The build is accurate to what a ukelele looks like, so good job on that!
The parkour is the main issue with this map. The parkour is varied, but not mixed very well at all, and gets very repetitive. Create the parkour in such a way that the map can't be cut into sections by jump type (the fence section, the water section, etc). You can see examples of this executed at /warp beta on the server, or recently accepted maps in the Accepted maps subforum. The parkour is also very inconsistent difficulty-wise. Some jumps are suitable for an easy map, and others are extremely hard, even for an insane. The parkour is too short for an Expert or an Insane map. Please make sure you check the map requirements before you build a map, as there's helpful tips about length and difficulty there! It is best to have a single difficulty in mind while building to avoid inconsistencies.
Thank you for submitting this map! If you have any questions, feel free to message me here on the forums, in-game, or on Discord.