A bit odd to say the least.
Normally it`s a case of when you download a game the set up or install of it is smaller in physical size as you know Mk.
Because a lot of the files are archived or compressed then expanded when installing the game to a hard drive.
Unless there were multiple paths or directory's created during the install of the game that are in fact not installed under the root directory of the install.
That`s about all I can think of.
For example it may of created a set of folders that are not found or located in the program files x86 directory.
But also the Program files directory.
Or windows system 32 directory of windows and also the SYSwow64 folder.
For example a 32 bit version of the game or 64 bit version of the...