There is no way to clone or copy only the OS files unless ALL of the data you DON'T want is on other partitions on the same drive. You can exclude folders, but if you are talking about installed applications or games, no, you can't do that. They will all have registry entries and linked folders and nothing will work right. Your BEST option would be to back up everything important to a NEW drive, AND to your old drive, so that you don't lose any of it, and then do a clean install to the SSD.
UNLESS the total size of the C: and other partitions on the HDD is less than about 70% of the size of the SSD, it can't even be cloned to it, at all, without removing a lot of installed applications and games. What is the total size of your current used space on the C: partition?