In an attempt to further monetize its iOS gaming portfolio, Electronic Arts is releasing a freemium version of the popular real time strategy game Theme Park on iTunes.

Although the game is initially free to play, if you want to upgrade your park quickly, you are going to have to cough up some real cash, with some single rides costing the equivalent of $60.

This move comes hot on the heels of EA’s decision to introduce a $30 a year subscription fee to its Tetris iOS game.

The game has not yet been released in the US, but Canadian iPhone owners can already get their hands on it. AOL has reported on the game, in which you build your own theme park, by choosing shops and rides, and says that progressing without spending any real money is a painfully slow process.

Users sticking to the free features in the game are able to unlock a limited selection of attractions, but any really ‘cool’ items cost Tickets, which are purchased with real money. AOL states that a Skull-Train roller coaster in the game costs the equivalent of $60 to purchase, and that the majority of the game’s rides are just as expensive.

There is certainly money to be made in the freemium game market on iOS, with Smurfs Village  and Tiny Tower both having proved their worth recently. Whether EA can replicate its Sims Social Facebook success on iOS remains to be seen, but with the average transaction value for iOS or Android purchase at $14, they may be a little off the mark.