There are keystroke logger programs but one of the easiest ways is the fact that Win keeps a record of the last time a file was accessed. So you can just go to the folder where the game programs are stored, right click on the executable file, click on properties and there you are - date and time created, modified and last accessed. Or if the icon to access the program is on the desktop, you can just right click on the icon and proceed as above. The info is on the "General" tab.
.bh.