Rainbow Valley's local authority won't allow any landscape changes or large tree removal, but you must develop the area into a large theme park.
The park itself is located along a river, long, but not very wide. The terrain is hilly, and there are a lot of trees. As the description already made clear, the player is not allowed to remove any scenery (including trees) or raise/lower the land or water level. Therefore, the space available to build is very limited. There are a few small cliffs available for building underground. This park seems impossible at first, but if you get used to it, it may be a cakewalk.
Rainbow Valley has no pre-built rides.
If you set your research to $400 for the whole game, you will finish all research in October, Year 4.