One of the tricky parts of mixing a game is that to listen to the audio you need to play the game. And this takes up a certain amount of brain power. This could be solved by having someone else come in and play the game while you watch/listen, but that’s not always an alternative.
So what I’ve done lately is to open up a Reaper session and route my soundcard output back into the mic inputs of the same soundcard (using two 1/4″ to XLR cables) and record the audio of me playing the game. I then exit and listen to the audio alone. I’ve found this very insightful during the mix process.
Two notes on this:
1) The routing above leaves you open to a feedback loop so ensure that you are monitoring output only through your soundcard and do not have monitoring enabled in your DAW.
2) I am NOT trying to advocate the separation of sound and image. If you make sound for a game – you are making sound for that game. The feel of the audio whilst playing the game in the most important factor. I am simply suggesting a way to gain an ecstatic perspective on your mix to aid your decision-making process when you continue to polish your audio.