Hello,
If you give WRobot a .cs file, you cannot use newer C# features (like 'using MyNamespace;').
To use these new features, give compiled files to WRobot (dll).
'public class Main: ICustomClass' must not have a namespace for WRobot to find the class.
For example, you can look at this code to see how to separate your code into several classes : https://wrobot.eu/forums/topic/11961-fightclass-framework-for-243335a-and-more/