Image source: ps4home.com
Analysis
Adaptive music - as far as I can tell, a randomized sequence of pad stems is playing at all times, the selection of pads possibly dependent on the depth. On top of that, all gameplay events start other musical stems that act both as gameplay feedback and as music (similarly to Rez). The pads and the gameplay-triggered stems are not necessarily in the same key, so it sometimes sounds a bit harmonically messy.