Your game will be installed along with all other Modern UI apps in C:\Program Files\WindowsApps, but be aware that this is a hidden and protected system folder and should you need to view it or make any changes you will need to do a bit of permissions-changing which Windows will complain about a bit.
There shouldn't be any real reason to do this, but should you ever need to confirm an install or check if a file exists, etc., the info is here: http://www.wikihow.com/Access-Metro-Style-Apps-Installation-Folder-in-Windows-8
Please note that Windows can seemingly reset the owner back to being the system also, so you may need to re-apply these changes in the future.