Build Your Own Six Flags Park/Scenario Guide
This is the pre-installed scenario that comes with RCT2 that resembles a sandbox the most, being almost completely flat except for a water feature in the middle of the park boundaries as well as some hilly terrain near the back, and with multiple rides, stalls, and scenery/theming objects immediately available. The starting loan is $10,000 and can be increased all the way up to $100,000, which should be sufficient to build most ride designs. This is also a park entrance fee scenario, so the rides are free. The relevant section in Hints and Tips contains additional advice for scenarios like this one.
First, uncheck Shops & Stalls from research priorities. The park already has a wide variety of shops and stalls available, so research should be focused on other areas. Next, build a ride or two—a Merry-Go-Round and small roller coaster is a good starting point—before opening the park. Set the park entrance fee to $60, which is the lowest amount of cash a guest will start with in this scenario.
A prudent approach to developing this park is to start small. Although the loan interest is only 5%, building expensive ride designs (like the larger Six Flags coasters such as Texas Giant) will cause the amount of interest to add up quite fast—maxing out the loan limit incurs a monthly interest fee of $2,000, which is extremely high at the start of the scenario and likely to offset any profits made. In addition, the number of guests visiting the park is determined largely by the number of operating rides, not the size of each ride. Hence, building a decent number of rides that are flat/compact and cheap will keep a constant flow of guests entering the park, providing a consistent source of income. The loan interest should be manageable once monthly income exceeds $1,500, at which point larger, costlier rides can be considered.
Given the size of the park, as well as the availability of many common Scenery/Themeing objects right at the beginning of the scenario, it may also be worth "decorating" areas where rides are going to be built, as well as dividing the park into little "themed" zones. While making the park look more realistic has no direct effect on the guests, they still respond positively to high amounts of scenery objects placed around the park. This may occasionally cause the park to receive the "Most Beautiful Park" award, which increases the number of guests entering the park for about two months, even if no new rides are built during the period.
The objective requirement of getting 1,500 guests in the park by the end of Year 4 should be quite achievable as long as new rides are constantly built and a balance between income and expenditure is maintained.