The ending definitely didn't pan out the way you intended. Since I didn't really have an idea of what's coming next when I feel down, sitting still didn't feel like the best option, so I just got thrown into the abyss. Some forewarning in a future map would be nice.

Have you gotten to the 400 m in the main map? There's a really neat part that makes you go downwards to climb a bunch of ladders, and let me tell ya, it is stressful. I think something like that could fit well with this concept.
Furthermore, you could take a look at the main map to get some inspiration, because the dev utilizes the entire space very well. It's not just a vertical climb, but it also makes you travel up down and all around to make progress. Something to think about going forward. :)