The GoVideo extension does not directly record system sound from your computer (For example, the sound effects of a video game or music playing from a video).
Your GoVideo recording has no sound other than what is picked up by the microphone.
The product is working as designed.
GoVideo can only record the sound picked up by your computer's microphone.
You may choose to use external speakers so that the microphone can record system audio. However, this may result in poor audio quality or sound feedback.