On Seattle Default City on Max Shaders I get 27 fps.
It would be higher if Blockland wasn't so reliant on the CPU.
I get ~30 FPS as well however I don't think it's only about being reliant on the CPU as much as it is being able to manage it's resources correctly, engine-wise.

The green line on the top shows GPU usage, which barely reached above 60%, the green line on the bottom is the cumulative CPU usage, which likewise barely reached 60%. On per-core performance, most of the cores were relatively equal, except the first one which used more (I remember Badspot explaining what each core does but the first one is the most used anyway) but it still didn't reach 100%.
Yellow line at the top is the Video Memory usage, nor which it reached 100%.
Blockland doesn't use a single core at 100%, or the GPU/VRAM at 100%. The only thing that gets close is the first core at around 80%.