Note that the audio recording and video recording may drift in and out of synch if the video does not play at an exactly consistent speed. By using the “New Length” control in the Change Speed effect you can ensure that the overall length matches.
Of course it will, because it IS sped up.
Even if we have an effect that can speed up sound “perfectly” without changing the pitch - imagine if we have a recording of someone talking - speed it up 4 x and it will sound like they are talking super fast.
The only way that I see for making the recording “4 x shorter” without “speeding up” is to do lots of time consuming manual editing - if there is a sound effect that loops 16 times, cut it down to 2 times. If there is a tune that repeats 4 times, cut it down to once only, and so on.
Alternatively, just scrap the “in game” sound. Record yourself reading a “talk through” after you have finished playing the game, mix in some music of your choice, and add you talk-through and music to the (silent) video.