
These are actually the same frame, just split into two for compression's sake, if you get what I mean. What I do is rotate 90 degrees, then stretch horizontally 200%...

...then delete every second line...

...then overlay the two images over each other so that one fills in the missing lines on the other.

Sorted! A perfect rip, direct from the ROM! Well, sort of. Some frames are split across multiple files, and the pickups tend to be stuffed into the corner of other frames. Still, a strong start.
As an example, the Raptor's death frames.

I'll see what else I can do and whether I can automate this further.