Huh, interesting. Good to know. At this point, you’re probably right that it’s the graphics card. When I talked to Andy Watkins about it, his position was that at this point issue of actual GPU support should be really rare (the GE FX 5200 is over 15 years old! - a computer that shipped with that card will probably be running an OS that’s out of support, and generally be on its last legs).
While the early puzzles aren’t graphics intensive, our current labs are actually quite resource intensive due to their large size in the thousands of bases) - before the PIXI upgrade, even with WebGL enabled, you might get 5fps on it. Falling back to canvas or having a less-capable graphics card would doubtlessly make that even worse. Now on my system I’m able to get up to 15-20fps - still not great, and would be worse without WebGL. We still have more we can do to improve performance, but it isn’t a nonissue. Not shipping with Pixi’s canvas fallback/compatibility version also means that the download size is notably smaller. Another benefit is that there is a class of graphics features (ie, shaders) that require support of recent webgl versions/extensions. We don’t use them a lot, but it’s another part of the consideration.