The best way to get better at programming is to spend time doing it on your own. Being a professional programmer is a lot of work. I know it sounds cliche, but it's really true. Find something that you're passionate about and create some code. You said you're interested in learning more about game programming? Create your own vector/matrix library. Or build a simple game in XNA. Over time you'll learn a bunch of new stuff and that knowledge will become useful as part of your portfolio and in future interviews.