Today I just focussed on level design. I got a large amount of level 4 blocked out very quickly, because I was using a slightly different strategy for it. I went back to what we were taught in college and used geometry to block out the design and left the static meshes and blueprints for just the major gameplay elements. In this way, I gave myself a lot more options for making levels different from each other. For this level, since it is accesssible from both Level 2 and Level 3, I wanted to make sure to include the flying ship mechanic again in another introductory section.
Having blocked out the level, I then set about adding routes and obstacles. I included one safe but long route and one short but risky route. I also added two flying ships and decided to use them to theme the level around a port city kind of aesthetic, with ships and boats transporting crates to various places, and the building being really just for workers to get to the flying ships. I still haven't really settled on an overarching story except for Nueva Venicia being an important city, but this theming of the level helps both me and players make some small inferences about the story of the world the game takes place in.