Theme Park is a bit complicated game, both on gameplay and making it run on newer Windows versions.
It's good to see some people like it too, though!
From what i could see on youtube videos, the older console versions weren't as good as the original game or the DS version. The Super Nintendo and Mega Drive versions are just horrible. The Playstation and Saturn versions were way better and almost identical to the PC, although it seems terrible to design a park using a controller instead of a mouse. The DS has great flow and the menus are very appropriate to the stylus, which fitted like a glove to this game.
About running the original DOS PC-CD ROM on recent Windows, you gotta use the DOSBOX and make a few adjustments there so you can install and play it properly as it was running from an actual CD (while using a ISO from the original game). It´s a bit tricky but it works, at least on Windows 7.
About the gameplay, the game can be short or VERY long, depending on the game style (sandbox, sim, full) and difficulty level (easy, normal, hard). I'm playing it on the sandbox style and even so it's a very demanding game about taking care of the park. The objective is to create and manage a successful amusement park on several countries until you reach a certain money quota. If you choose the "full" style, 9 competitors with high level and the "hard" settings, you could spend months playing to finish the game!
Even so, if you pick more regular difficult levels, the game might be challenging and fun, if you have the patience to manage several parks, one after another.
HarvestDude™