Carnival Sim Game?

I am toying with the idea of trying to get a carnival sim game out and wanted some reaction to it.

What types of mechanics would you guys like to see in it? Specific rides, behaviors...stuff like that.

Would you want it to be a freemium game like farmville or would you rather it just be a purchasable game.

I have seen different Carnival Sim game son the itunes store and they don't seems to do very well....is there anything you might suggest I do to make sure I don't fail as badly as they have?

Looking forward to your thoughts.

Controls must be smooth, responsive and accurate. Also check out this game http://www.gamespot.com/pc/strategy/...oon/index.html make it sortof like this, except better. Also be sure to ibclude plenty of platable minigames, you can use it as a selling points

Mini-games are always good, like Thrillville but with more SimThemePark style construction. Oh, and you'd probably get more downloads as a freemium, but personally I'd prefer paid app.

Karnival on the app store has been in my wishlist a while, but the word 'crash' is all over the reviews...so I can't really give appropriate feedback comparing it to that game since I'm hesitant to buy it.