I've been playing with GameGuru for a week now and I noticed something that could easily enhance the performance. Here's my story:
I created a map of a city with a warehouse (one that has stuff inside) on its perimeter. No matter where my character stands on the map, when he faces the warehouse, the amount of draw calls jumps to 1600 and frame rate drops from 40 to 15. This happens even if there are buildings between my character and the warehouse blocking the line of sight. I think these draw calls are completely unneccessary.
(I know I could just create separate maps for the warehouse and the city, but I think this optimization would boost the performance of the engine in other situations as well and enable the engine to hold large maps properly.)
So my suggestion is that you would limit the draw calls only to objects that are actually visible.
Edit: Explanations for attached images: 1. The warehouse. 2. Some buildings in the opposite side of the street. 3-5. Player standing behind the building facing the warehouse.