How to present a review paper at a conference?
In 12 minutes, the best you can do for your audience is highlight four to six broad observations or conclusions about the state of research. Here are some questions you might address with your observations:


Are the lines of research diverging and multiplying, or converging and consolidating? 
Has it divided into "factions" or "schools" that define problems, methods, and solutions differently?  Or is all research operating under a single paradigm?
What's the influence and interaction with other fields and disciplines?
Where has research made progress addressing fundamental questions?  Where has research made no meaningful progress?
Where should researchers look for the most promising research directions and under-explored areas?


Don't try to make more than six observations in 12 minutes. By trying to say more, you are actually communicating less effectively.  Any one who wants the full story can read your paper.