Is it possible to record game audio, + your voice, + a skype call? like if you are doing a co op game over internet and you are in a skype call to communicate.

If you're on Windows, putting "Win 7 (WASAPI)" as one of your audio tracks and "Microphone" as the other, will allow you to record Skype calls, game and your microphone. (WASAPI is "What your hear").