Right now the game takes place in an underground base. When you see the mountains, that's on one of the few corridors that actually have a view of the outside.
Unfortunately I can't move that corridor earlier in the game without redesigning major parts of the map. Especially the first area of the game, which houses the tutorial. Alternatively, I might have to break the established shape of the base to excuse an outdoors corridor several kilometers underground. I did think of improving the background of the starting room, but I would need more funds to do that change.
As far as enemy attacks go, there are a few enemies that do actually have some more distinct patterns or behaviors. The Spinner fires projectiles in a spiral, the Javelin fires projectiles that bounce off walls, the Knight fires projectiles that explode into smaller pellets, and the Stinger just rams into enemies with their Energy Spike. Most appear later in the game since they're more difficult to fight.
I actually do know Fiverr, it's where I found the artists that did the Title Screen art, the Ending Screen art, and most of the ship models. It's a fairly good platform, and I was planning to use it for the Steam achievement icons.