Google play games in Javascript?

Hi all, when I almost finish my game in JavaScript (I choose JavaScript because, my background programming language based on Java and Js.) then I decided to add Google play games feature so far so good.
However, I realized that Google Play Games plugin written in C#, what should I do now? I googled already this issue before I asked in, but I did not find useful information.
Is there a possible to run both scripts in JS and C#, for example I have a 5 scripts some of them in JS some of C#.
or
Is this possible to C# class in JS file?

You can have both types of scripts in a game running simultaneously. I have about a dozen of both running in my game demo.