Something which I've never done before, is animating leaves, turns out it is easy, just draw curved lines and paint a rotating leaf over them.
The default mode is genuinely quite hard. I selected default and that was probably a bad idea. It did feel nice when I finally beat the boss, though.
There's an easy mode that I would highly recommend you select. With the easy mode, there's difficulty sliders that'll change the amount damage taken and received. The range on the sliders is extremely wide, to the point where if you set the sliders to their extremes, I'm fairly sure you're essentially just invulnerable
In any case, while the combat is quite a highlight, I think the story is the real star of the show. I would highly recommend the game just for the story alone. I'm of the opinion that Nine Sols is an underrated masterpiece, even better than Hollow Knight