Basically this level I'm working on is an ice desert. These exist on Earth, except nobody in their right mind actually builds pyramis on them.
The approach I'm taking is introducing a few enemies first, then mixing them up to make gradually trickier obstacles. Here some pics with the bad guys:
As you can see, this kind of pokey resists cold temperatures. Also I'm not sure about that bottom gradient (perhaps because of the second brightest color).
By the way the bushes are supposed to be just a bunch of snow.
Introducing timed lifts (and caped koopas). I don't know if I'll actually use them, but I had some ideas for the later parts of the level.
Also cold flames because why not. They are kinda tricky to work with.
Spoiler: there is a freezing pyramid section. I'd like to make the inside slippery, but if it proves unbearable I probably won't. Note that the outside isn't actually slippery.
That's all for now.