You'll still need to tend to the business aspects of running a park, but that's been made fun, too. The rides need maintenance, so you'll have to hire staff to keep them running - but thankfully, the training sequence is a minigame unto itself. Same goes for the groundskeepers: strap on a vacuum and suck up the papers and empty cans yourself for a few minutes to train your main trash picker-upper. Once he learns, he'll train other personnel on his own.
Building and riding the rides is clearly the main hook (in addition to the mission-based game mode, there's a Blueprint mode that lets you build and test wacky creations just for sandbox fun) and, while this could have been a chore, our demo showed how easy it was. Shuffle through track segments and tack them onto each other; if one doesn't fit, it'll turn red. Just try another. If you get partway through building a ride and sort of lose interest, simply ask the game to try to finish the track for you. And if you build a ride that's, you know, impossible, the game will fudge the physics for you rather than strand your train on the tracks.