Excellent work! This is an example of using technology to actually increase usability, WOW factor, and salability of the products, instead of “torturing the user” like in most cases.
My low-range old PC + a relatively recent low-mid range graphics card (GTX1650) runs it fine.
Apparently your friend might not have a graphics card at all - it might be embedded In the motherboard using the CPU display features or something.
What are his/her PC specs?
About the 3D load time, on my 50Mbit line it took 14 seconds on Edge.
Then I disabled cache, waited for the main page to load, and after hitting “preview” it took 22 seconds. There is obviously room for optimizations here, as in an older ~10Mbit line it might take 5 times longer.
That said, loading time might be affected by my weak CPU.