First of all, I remember your post on urch, so its good to see that you are still applying. The only advice i have for you is to apply far more widely. I have advised other Indian students about the the same thing, and nobody ever listens, but here goes nothing. The competition for top schools is tremendous, and putting all your eggs in these risky baskets is just a waste of time and money. Look at tier 2 programs too, they often have great faculty and a less cut throat environment.
Also, flesh out your research interests. Gamification is a bit of a buzzword, it would work in your favor to have a substantive research agenda going by the time you apply. See if you can get your undergraduate professors to recommend you. Letters from junior faculty, that too lecturers, may not be of much value.
good luck!