To me, this looks like a blue recolour of a standard grass tileset.
I think the slopes could use a bit of a more wavy shape where the top part meets the fill. It looks really weird like it is now, because the connecting part is uneven throughout the rest of the tileset.
Ideas are useless if you can't make them real.
All my assets from packs and episodes are free to use for non-Novaverse levels and projects, as long as proper credit is given.