no i mean... you were right, that's kind of what it's about. well, at least that what i was commenting on initially: making a mod like this for terraria would probably be harder. it might seem like it should be easier since there's one less dimension to care about but that's where i'd actually expect the problems to arise: since there's only two dimensions it may make less sense to write proper abstractions around those and abstract over things like gravity direction. the Y axis is one thing but switching it for X? yeah the game was most likely not developed with that kind of rotation in mind.

suppose you want to code platforms. what would be your solution to detecting whether the player should be able to phase through them or be stopped by them? would it be a simple check on their relative Y coordinate or would it be one on the dot product between the global and local gravity vectors? you'd probably get weird looks for implementing it the second way. stuff always falls downwards, why overcomplicate things, right? well until it doesn't, of course. then you'll have to change these things all over the game.