Why put a single new flat ride .. usually it's 2 - 3 see a little more ...
There isn't any flat rides, there's 2 coasters (well, 1 with 2 different trains) and 1 transport ride.
According to Bo in the "World's Fair Pack" thread, rides take too long to create and are time consuming / cost a lot of money, but hey, hopefully with this Thememakers Tool-kit, Frontier will stop pushing out themed packs nobody asked for and start releasing free ride updates / ride packs (hopefully more generic) and maybe they'll work on things like fixing coaster cams/smoothing, scalable splash downs on water rides and scalable coaster pieces like the lift on the eurofighter & boomerang coasters.