Nice! Have you explored showing live values flowing through the nodes? This seems like a good use of animation.
I'll also take a moment to plug my Visual Programming Codex[1], which collects VPLs as though they're butterflies. I'm adding Flyde to the backlog of projects to document, but I'd also suggest looking around there for ideas. There are a ton of valuable new things you can do once you start visualizing programming, especially if you're visualizing the execution behaviour. I'd love to see you push this further.