Blockland v2 uses TGE 1.2; 1.3 is a significant improvement.The most significant improvement in TGE 1.4 was an optimization of ray casting vs interiors that makes it possible to have complex interiors without the framerate going into the toilet every time you shoot a projectile. I have ported this fix back into my version of 1.3. I addition, I've fixed a number of things that aren't fixed in any version of TGE. I've entered some of these fixes into the GG internal bug tracker and eventually they will make their way back into the engine.The biggest problem with 1.5 is performance. Something is crapped up and it's slow. Eventually I'll port Blockland up to 1.5 and find out what's wrong, but at this point the benefits are not worth the time.