Holy image dump, Batman! I took a ton of pictures at Mitsui Greenland when I visited in May. The park is huge - the rides are spread out in an area that must be as large as Manhattan. And there is a large number of rides to choose from, with several coasters and other attractions. The park feels like somebody played "Sandbox Mode" on Roller Coaster Tycoon and just plopped rides down all over the place. Let's see what we find.
Mitsui Greenland is located in Kumamoto, and is reached by train and then bus. Because of the large number of attractions, it's a good idea to spend a whole day there. If crowds are light, you can get your 10 rides in on Megaton and take the bobsled down the hill a few times. While there are no real standout attractions at Greenland, the sheer quantity makes for an enjoyable day.