I am at a loss to hear anything nightmarish here; rather a remembered ecstatic dream or vision perhaps. The main texture of short, background chromatic phrases against clear melody and the occasional rich, shifting chord is powerfully evocative, and is the stronger overall for being interrupted by the several brief episodes of contrasting texture. Its brevity is in fact an advantage, as the listener is more or less compelled to hear it repeatedly to fully absorb its beauty.
The file needed fiddling in Audacity to balance the stereo tracks but that is a very minor point and easily fixed.