Features and Performance
For the most part, NatureArt is extremely easy to use, and the interface is very intuitive. Every effect has at least one preset configuration, so it's very possible for beginners to get started right away with "one-click" alterations. However, most effect applications will require at least some adjustment of the various parameters – but this is also fairly easy to learn.
Each parameter is controlled by a slider that you can manually adjust, with different effects governed by different types of parameters. What's really nice here, is that if you hover your cursor any of the various parameters, a basic explanation of that control will be explained in the yellow box found at the lower right corner of the screen. Still, I think the easiest way to figure out what each slider does is to play around a bit with the different settings and see how changing one affects the entire image.
My only real complaint here is the lack of a preview window to give you a basic idea of how the image will look without actually applying the changes. If you're working with small images, this isn't too big of a deal since you can just apply the changes and "undo" them if you don't like the result. However, larger images require more time for processing, and it can be a little frustrating to wait for the processing to finish whenever you just want a general idea of what a certain setting will do.
Also, I wouldn't mind seeing a few more presets built into the software, especially for the Sun and Lightning effects. Although, I do love the fact that you can save your own configurations, so when you do find a look you like, you can use it in later projects without having to recreate it from scratch.