Right now level backgrounds are very bland, almost nonexistent. The passive background creatures and floating chunks of ice are nice, but we're lacking varied, immersive backgrounds which could make each biome feel more unique.
Alongside these, I'm also suggesting that structures should intentionally be generated encased in level's walls in some cases. If the interaction between hull boxes and level walls around them is fleshed out (it doesn't work all that well right now), outposts might end up looking a lot more reasonable with the new generation method. Currently they generate as weirdly shaped structures with nothing in the background and can be approached (and flooded) from any direction.
But even without that, generating some background chunks around structures would already be great.
Last image is a more detailed example of a background structure that could appear behind an outpost.

