Look at #ImHex, they have achievements!
The source didn't seem to use the file format, and it didn't answer much... So I'm a bit stuck about the floating point. The result I'm getting seems accurate enough for now, though. Much better than the previous attempts I've seen!
#ImHex 's scatter plot visualizer kept crashing... I can't seem to figure out how to drive it, but I whipped up a python script and it looks like my current assumptions about the shape and position coordinates are "good enough".




