RTP = Run Time Package. Basically, it's the resources given to you when you install RPG Maker. It's bad because it shows a total lack of effort on the creator's part, due to them not looking for other tilesets and sprites to suit their needs, or even making their own. In some projects, this is okay because the game's completely unique and does show effort. With these, however, they look like they were done in 5 minutes simply to keep the topic from being closed.