The game is an MMORPG, the same genre as WOW, most MMORPG gmaes are similar.
The download is quite big. Its around 3gb I think.
I don't know about winning the items, but you can get them without paying real life cash. Usually you would need ZEN (but from perfect world entertainment, company that runs this game), then you would use the ZEN to get credits for the store. In Forsaken World these Credits are called Eyrda Leaves. Now Eyrda leaves are themselves an in game item. Instead of buying them with credit card, you can buy them from other players using the in-game gold.
Ill add this to the pros list!
Also, On the steam version, I think you can only buy these credits with the steam wallet.