Charger18

It's faster for smaller requests that come in from lots of concurrent connections, Node is not as good at heavy lifting as ASP. But when it comes to smaller size packets of information and concurrency it is faster. As far as I know at least, I could always be wrong.

Edit: Also your argument for it being better compatible with C# is interesting. I too would like to know why the developer went for Node now.

Not to answer for the developer, he might have different reasons. But Node is one of the fastest and most efficient concurrent connection frameworks which makes it great for games.