Wine application use more memory than the original folder before being "wined"

Recently i have a Call of Duty game from my friend in a folder sized 15Gb. After discovering that it's an .exe, i try to google how to make to make it possible to play it in Mac, and i found the application Wine, which will remake the folder into a single icon ready to play on mac.

after wine-ing it, the "icon" costs another 15Gb. However i found out that my memory had been used for 45Gb (should've be 30 Gb only). Since i can't afford -45Gb from my scarce space, i decide to remove Wine, the " wined icon", and the original folder hoping i will get back all 45 Gb, however only 30Gb returns, with the 15 Gb dissapeared in thin air despite no trace of any wine/CoD left.

can anyone tell me what's the problem and how to get my 15 Gb back?