Mystic Mountain/Scenario Guide
Players will have to build as compact as possible, as obviously, the park is small. There's land available to buy, but it's really expensive ($90 per tile), so expanding the park before the initial space is covered, shouldn't come to mind at all. As a matter of fact, this scenario can be beaten without purchasing any extra land. Later on more money will be available for purchasing extra land, but it shouldn't be necessary.
Another big trouble this scenario has to offer is that it rains a lot here. So building underground and indoor rides (such as Haunted House or 3D Cinema) is a good thing to keep in mind. An underground rollercoaster (like in Katie's Dreamland) is a probable must-have when facing this issue, as well as an important network of Info Kiosks and an extensive use of the umbrella cheat.
Flat rides like Haunted House, 3D Cinema, Bumper Cars and Motion Simulator are rain-proof and will not be avoided by guests when it rains, so these rides are must-haves as well. As for tracked rides, they don't need to be completely underground in order to make them rain-proof, but they need to have most of their sections underground. Some vehicles for these rides (Trucks for the Car Ride, per example) are rain-proof by themselves in OpenRCT2.
A reasonable option when building some coasters is to build them in powered launch mode or reverse-inclined circuit mode because even though they usually don't have a very high Excitement Rating, they will be shorter than continuous circuit coasters and become solid money-makers while attracting more guests. A good idea would be to build a Shuttle Loop coaster so that only a few bits of the station exits off the ground, while remainder of the ride is underground. This ride will never run dry of guests, and will rake in a lot of cash if priced correctly.
At the beginning, research and building priorities should revolve around thrill and gentle rides, with a small roller coaster (preferably a cheap one such as the Steel Mini). Slowly expanding the park's infrastructure as new rides are researched, and parcimonious use of Ad Campaigns would give the player plenty of time to reach the 800 guests demanded.