For all we know, this performance was cut together from save states or involves some form of tool assistance. We really can't know without the original INP. If the INP is on that ReplayBurners site I can't find it.
The original INP file is attached. It is a MAME .78 replay, but it will play back fine in WolfMAME .78 which you can download at
http://wolfmame.marpirc.net/wolfmameplus-078.zipYou'll need both the mappy and mappyj romsets to play it back as it is a mappyj replay. As others have commented, this is on the Japanese romset and on difficulty Rank A. This isn't suprising since it's a Japanese replay and Rank A is default settings, and Japanese players usually use default settings.
I don't know much about the background of the recording and whether it might have been tool asissted or not. Some of the Japanese members (or GEMANT) on MARP might know more about its origin and authenticity. I first saw it in 2004 on a now defunct Japanese replay site. Here were a few comments on the site (translated from Japanese) regarding the replay:
Post #1
Mappy no mistake 50Round
MAME 32Plus!0.78
My friend did it for me.
Post#2
The sophistication of the feel of the cat leading the way, including outside of the screen, the way it avoids 6000x2... It is impeccable in every way. I will make it my family treasure.
Post#3
Too good to be true.