The tweet popped while I was doing mental checks on my revised tiled engine, and especially how it would handle more slopes than the previous one: Ishi(soft) finally decided to introduce slopes in Leilani's Island. And while I was looking for convenient ways to encode more than one array of tile_height[type][offset], I was surprised that his approach wasn't not requiring any such array.

(C) IshiInstead, the world-collision engine would detect sloped ground and generate sort of "lift" objects that are tied to a specific X location, but adjust their Y location to the X position of the character that triggered them. It allowed enough flexibility to make me think twice before dismissing the approach. One of the benefit of the approach is that the code running the is-there-ground check still happily believes the character have solid ground all around them: This fixes the problem with enemies turning around on slopes. When they do their collision check, they find solid ground in front of them - because as far as they're concerned, they're on a flat surface.
There was one major restriction, though: Ishi decided to go for a single type of slope (22.5°) where X-to-Y offsets function can easily be computed by shifts and additions. But I personally want more. More angles and some curved ground as well. We could still have that in Ishi's engine, but it would require picking a tile_height[offset] array according to the slope type and pass it to the "lift" object....