ZenGL

[Andru]

With Game Maker, which is notoriously slow, it can still handle drawing a max of 6300 sprites at 30 FPS

What sprites did you use in Game Maker, and what about sorting sprites by layers(in Game Maker)? Also, give me a log file please, and info about your PC. And if you can - attach "benches" here(with sources and exe for Game Maker bench ), please.

I think ZGL needs some optimizations somewhere.

Rendering in ZenGL is well optimized, be sure. Seems only Sprite Engine have some "problem" with stable sorting algorithm, or something happened in your benchmarks