i mainly remember it because it was a detail the devs highlighted as part of their overall design intentions (here, although the site layout seems extremely broken for me now). i think Rain World does a similar thing at parts, though its world is a lot more chaotically organised.
A strong desire we had from the start was to give players a sense of place simply by looking at the graphics. Environments were to flow over into each other seamlessly. Ideally we’d also be able to give players a sense of where they were going by already showing landmarks in the background, which isn’t easy if you only move sideways. We thought about bending the 2D map, so you could see a landmark you’d visit later on in the distance, but again it didn’t feel like an elegant solution.
This desire to foretell what was going to happen brought us the solution to the problem, as we suddenly realized we needed a 3D map in which every level was a 2D slice.