#i mostly went into textures here bc ds games are much lower textured than psx or similar most of the time //

[bubblebaath]

hmm... im sure someones made a good guide out there somewhere, but i personally havent used any but thats not a good answer, so another place to start is to use a real game as a ref! this is the sims 2 ds:

most of the detailed textures are only used for the player sims hair/face/clothing you can see by the jagged edges of this sims vest that its still a little lower than the faces texture (this is probably because the body has more clothing variations than the face and they needed to save memory)

static parts of the environment have a higher res, because they can tile/repeat the textures. this game has a million variations on bed/chair textures, so they're notably lower res this is a ripped texture of most(?) of the things used to make an area in the game (image credit) :

the desert background here is just a 2d image, relatively low res because the player will never be able to reach it

i guess this is just a long winded way of saying "things that arent that important or the player will generally be lower poly + less detailed" but i hope it helps a little