I never tried Unity3D and I heard it's the easiest 3D game designing program out there, how easy is it? do I still have to know general/intermediate knowledge of coding?
Yes, you need to know C# or Javascript. Javascript is way easier. Hell, even I know some Javascript and I'm not a coder.
Other than that it's kind of like Construct. You you create objects, import models and sounds, drag them into the scene, write event sheets (scripts), etc. Only it's 3D.
And yeah, even though it's the easiest 3D game tool out there it's still way more complicated than Construct though.