Hey there, before going ahead with your map submission review I'd like to inform you that I'm only giving you my personal opinion/feedback on your parkour map submission and my personal feedback will certainly not affect your parkour map submission in the slightest, I recommend that you take in my feedback to improve your submission if there are any flaws, you don't need to and you're free to ignore me but anyhow, before going ahead I'd like to mention that I'm a Moderator not a Map Judge so this is just my personal opinion and I am not accepting or denying your parkour map as this is only my personal opinion.
Parkour theme/detail - Before going ahead you can press f2 to get a screenshot on Minecraft, then go to your windows search bar and type up %appdata% then click . Minecraft - go to screenshots and drag and drop the screenshots into your map submission thread, easier than using your phone, etc. For the theme, there's a lot of maps with floating islands and a somewhat similar theme to yours, unfortunately, for the detail, you did a fair job, certainly does look like a toxic island to me, good job.
Parkour variety/difficulty: So for your variety, you've got some variety added in but personally there's not enough added in, try to think of something creative to add, maybe an anvil jump, bed jump, chest jump, water jump, etc! You've got a lot of floating jumps on your map that sadly make it look messy, try grounding the blocks near the ground at least or connecting them to something/making them lower, it will make it look better and less scattered, parkour does match easy difficulty, good luck! :)