Back in the day I wrote a bit about this format and since it’s rather interesting I decided to implement its support in my game tool.
Eventually I got it working except on two files that seem to have certain frame data unpacked incorrectly (it’s the feature that makes this format interesting in the first place—per-group order-1 Huffman coding). And for every file decoding seems to go past the data boundaries at the end so I insert some additional zeroes at the end of packed data to make it work (another fun fact – apparently last eight bytes of both opcode and colour parts of inter frame seems to be always unused). And it seems audio data is always coded as silence. The actual cutscenes do not make much sense either as it’s usually a static cartoon image superimposed over a 3D rendering of some lady in a tower-like structure (the game does not deserve any associations with Sierra titles so I’m not using other words to describe it). Sometimes her lips are moving (if you can notice it behind the other image), quite often they do not:
All in all, this is a rather weird format for a seemingly weird game but I don’t regret wasting time on implementing a decoder for it.