That's the gist of it. They're saying you cannot redistribute the materials, but you can edit them. You can use them for pay games. The pixel art is meant for XP so they will not work with other programs. But it's okay to use the other art, like the battlers, in non-RPGMaker programs. They want to be credited as "Etolier" and they appreciate being told about the use but don't require it.
It's pretty lenient terms, compared to some of the other sites.