Could've been much better.
Many of the glitches, since it's initial release have been fixed, I'll give the game that much credit. However, a great deal of the glitches such as pool lights at night causing lag and looking like crap, have yet to be fixed, because the developers "can't reproduce the bug" even though virtually every single player has been complaining about it.
Overall, the game is very decent, but unless you NEED the 3D game play, I would have to say, pass on it. Roller Coaster Tycoon 2 is a far better game, even if it doesn't have as much.