Different with other game made by blizzard, hearthstone is free play game, which means it works differently with world of warcraft which need purchasing in game time and other game that doesn’t have in game shop. Also different with other blizzard product, hearthstone is the only card game, instead control your avatar or soldier to fight, people compete others by play the card they have.
Economy: player can also expend they card storage by collect them, basically there are three way to do it, first is by earning gold freely in game and purchase card package, the other one is purchasing package by real money. meanwhile, there is a third way to earn new which card, which is recasting them, player can recasting their card to a new card which has different feature and function.
Culture: collecting is the main theme of this game, the reason why it is so popular is because it has a giant card system and trading system, player can always discover this big system by doing traction not only between other player but also the system. To make a idea deck, you need to came up your own strategy. A perfect combo can do much more then you expect. This is the main cultural element of this game.
Even though this game is based on the game warcraft, its game system has nothing to do with warcraft,.
I’d encourage you to look at the way the impact areas are described on the website, and make the justification on those terms.
For example the idea “Cultural Emergence” is describe with respect to games as follows:
Games provide a creative ecosystem for the wisdom of diverse cultures to be given a voice, purpose and place in history as well as our present day life.
So you need to identify how those ideas are captured in Hearthstone. How are diverse cultures represented literally, or metaphorically? How are they given voice? What can a player learn about how different cultures interact or how to become aware of different cultures by playing Hearthstone?
Hope this helps. Also, there is no “Economy” area, but I know you mean “Economic Prosperity”. The focus on models of prosperity is important, which is why i’m commenting. I think the ideas you’re identifying under “Economy” could be very nicely drawn out in a guide about different models of economic prosperity, so it is worth pursuing.