Neat idea! Between this and AFK I sense a (good) theme to your ideas :) This should be a straightforward implementation with the addition of the gravity mechanic only a minor complication (raycast to find opposite wall? literally just changing gravity which is fine if play is the only gravity effected character?). Obviously level design is important here and I'm confident based upon AFK that this should be straightforward for you. I would been keen if time to see if some pickups or extra bonuses could be added to levels to bring some extra fun? It's not strictly necessary to get a good mark here, but I'm wondering if there are any other mechanics kicking around in your head for expanding this one beyond what is described?
Regarding how the player will jump between walls, it’ll likely be a combination of a 0 gravity Rigidbody and coding the script. When the player jumps, it’ll apply a force away from the surface they are on, and when the player touches the opposite surface, it will reorient itself (possibly using normals?) to “stand” in the surface.
In scenarios where gravity is required (which might not necessarily even be used in the game), I’ll likely build a custom script to allow gravity in any direction, although it’d really only be used in the 4 cardinal directions.
I want to try and avoid Rigidbody’s built in Gravity system, as it only works vertically, whereas the solution I implement should support vertical and horizontal gravity.
As for other mechanics, I’ve definitely got a few in mind that could definitely lead to some interesting puzzles, such as the more typical electricity and moving platforms, as well as some strange mechanics too, like player death mechanics.
Unfortunately, I’ve not got many details to share on how these will be fleshed out, but I don’t imagine these’ll be too difficult to implement.