I create game backgrounds by taking a particular component e.g. wind, and cut it into shorter sections. these can be played back in random order and crossfaded in real time by the game ‘engine’. This means that, although the sound is looping, it never plays in the same order which helps to keep the sound varied, and prevents other ambient elements coinciding with each other. 

Sounds such as creaky building sounds, can be a group of one-shots set up to play at random intervals with pitch, volume, and low pass filter variation. The game engine can position these sounds randomly in the surround field, if desired.

In film sound editing we typically loop the different components of the ambience (such as wind tone, vent sounds, crowds, creaky building sounds, etc., which are usually recorded separately from each other) at different times so that the composite of all the loops, all looping at different times, doesn’t sound loopy. Can you do that easily in game sound? Or are you limited in the number of BG loops you can have running? 

The one-shot sounds which are part of the offscreen space I would consider part of the middle ground and are very useful for keeping the ambience interesting and varied. The more story or action related sound you have going, the less you need these one-shot type sounds, since there aren’t many empty spaces to fill when the track is busy for other important reasons.

If anyone knows of anything similar, let me know :)