By myst6re.

Particle Data

When this file is empty, it is only 4 bytes = 0x20202020. Else:

Offset Size Data
0 2 bytes Unknown
2 2 bytes Unknown
4 512 bytes 16 palettes
516 Varies Image Data

Palettes

16 palettes of 16 colors in native PSX format (R5G5B5 with one mask bit).

Image Data

The actual image data can be read as a single 256 pixels wide image, the height depends on the size of the data (height = dataSize / 128).