Micro-transactions in games
Micro-transactions is the way that studios get money for free games. You play a game of getting coins and unlock terrains, but gets a point that to unlock a terrain you have two options: The Slowest is that you don't pay and recollect tokens of the game of the classic taking you an unhealthy time in the game, The Fastest is that you pay to the game to get that token and unlock the terrain. Even if you choose the fastest way and promise yourself "Ok, this is the only micro-transactions i'm going to pay in this game" theres more chance to do micro-transaction not only in the game but in oder games. The two options is the way developers of this game wash their hands: The game doesn't force you to pay the micro-transaction, but in a point in the game is impossible to continuing or the time you have to invert is insane if you don't pay.
Here's a conclusion: You put the value of the game and you do in base that value. If the game doesn't worth the value that you put, quit it. doesn't worth it. Because if a product is free, the product is you.