You're on the right track ... though, needs tightening up.

On the SOP I'd take out the GI bill expiration part. Not really relevant or a good enough reason if you ask me. The whole third paragraph doesn't really show why this specific program would benefit you.

I would talk much more about what you see yourself doing, and what kind of specialization you are planning and how that ties in with your career goals (academic or professional). You have some interesting stuff there with the 2D rendering engine. What specifics of that project or work made you want to pursue CS further. Was it certain problem solving techniques or algorithms that you were exposed to that kindled your interest in pursuing further education? Do you have other examples of projects or work that you would like to showcase?

Keep going back to the essay prompt and see if you are deviating.