Pretty cool virtual cube!
With the most controls being the same as the controls in cs timer, it didn't take much getting used to for turning itself, and I love the default shades you picked. I also really like the UI and it was easy to navigate.
Although, as someone who currently only practices virtual, there are a few things that could be nice to have. Having an option for a "see through" akin to cs timer would make this more viable for speedsolving. And if there was a way to completely disable animations, that would also help. I'd have to solve more on here to know if the placement of the M turns would bother me, but having the option to have custom key bindings would be incredible.
If you ever are just bored or you just wanted to fully soup it up as much as possible, macro support for algs would be amazing. Being able to have a list of times could also be really handy. Some people would probably appreciate custom color options as well, but I love the default shades so much that I don't think I'd change them.
Overall, if you're just making this to be a web tool for people to check out, I think you did a great job covering the basics. Obviously, most people aren't super into virtual and wouldn't utilize all the extra stuff that I mentioned, but having those features would make this a viable option for virtual speed solving. No matter where you plan on taking this virtual cube, keep up the good work!