The Up vs. Down design issue in action games is most easily summarized by whether you are moving with, or against a restoring force.
Moving against it (up) will generally feel more challenging because there is the possibility that you will fall back to where you once were. The player has the possibility to repeat content like Getting Over It, or possibly fail quickly like in the first level of Kid Icarus.
Moving in the same direction as a restoring force will generally feel faster because the restoring force is aligned with your movement goals. Downwell falls into this camp. Can’t repeat content in Downwell!
In non-action games, the Etrian Odyssey series has you climbing the world tree as your goal in the first two. In Etrian Odyssey 3, it’s mixed up and you plunge deeper and deeper down into the world. I’ve spent a fair amount of time playing EO3, and EO5 (another “up” game). Progressing in EO3 felt more mysterious, but EO5 felt more rewarding. I can’t quantify it - it’s just a feeling.
Here is another game about going up:
https://tangramgames.itch.io/tobutobugirl
It’s also a “new” Gameboy game. I can’t confirm or deny it’s good though - haven’t actually played it.
