1)- Static World.
(no ability to make lasting changes within a game world from the player side. The status and shape of the world is developer perogotive).
2)- Restrictive Class Based System.
(Race/Gender locked into class/faction. Little to strict cross classing ability. Tierd class advancement. abilities/skills available and changeable dependant on chosen class).
3)- Limited Crafting.
(little to no ability to create/modify items are equipment accepting where it pertains directly to improving combative abilities. Heavy amount of account/character bound items. Ability to make better things tied directly to ones over all combat/progression level).
4)- Closed-end gameplay.
(Quests/storyline tied directly to progression (though not always enitrely nescessary to progress). Singular end-game focus. Heavy tendancy to force either solo or co-operative play. Little ability to diverge from prescribed methods effectively).
(Economy regulated by store prices. High end/priced/most frequent use items often regulated by careful control of a cash shop. major political social structure of the game and advancment of storyline determined by developers, often in the form of expansions. Low amount of player say or player made content in updates).
In my opinion these factors are the primary (or at least major) definatives of the ThemePark Sub-Genre of MMORPG's. And, should an MMORPG by large majority employ (4-5) these factors as part of it's aproach over a SandBox approach I consider the game to be ThemePark in Nature. Should a game employ a small majority/large minority of these factors in it's approach (1-3 or less). Leaving the rest of the 5 definative points to the SandBox side of things. I will consider it Sandpark (hybrid) in nature [as in: possessing a fairly balanced amount of features from both genres].