It is a scripting language, from what I've seen. Commands can be an arbitrary number of bytes, depending on which one. Now that I think about it we probably don't even need to know the method offsets- VBA-SDL-H has a function to break on reading a byte, which should let us find the animation code pretty easily.
Anyway, some of the ones I've been able to figure out:
00 XX XX: Loads sprite data. These are usually at the very beginning of the script, although there doesn't seem to be any obvious problem with having them in the middle.
04 XX: Delays script execution for XX units of time (frames? not really sure).
05: Halts script execution until currently running animations finish.
08: Ends the script. There *are* jumps in this scripting language, though since they point to a location and are followed by the address this means any block of script always ends in 08.
19 XX XX: Plays a sound. Might be able to play music if given the right parameters, I haven't mess with this one much.