not even cloe imo.....dont get me wrong this game plat is hallenging but hardest....nowhere even close....heck ngs2 itself utterly curb stomps this games diff in both challenge and in its plat. Im not making this sound like a cakewalk but theres plenty of other games that make this plat look easy even if its not --- Kool Kieth for president! https://www.youtube.com/watch?v=zeknB3ceRNA
If I recall right, the first thing I do is run-slide into the 3 cyborgs. Quickly enter Blade Mode and horizontally cut all three (preferably in one swing).
They drop Electrolyte Packs. Pick them up and use one quickly to recharge your Fuel Cells. Go to where the Gekko shows up. Now there are two choices.
1) Stand where he spawns, and counter his attack. He will dodge your counter. However, if you are in the right spot, he will jump into a wall, and your counter will still connect. This will open up an immediate Execution (the Circle+X prompt).
2) Try to draw his Bull Rush attack. You can block it (where you have to rapidly press Square to push him off), and it opens up an Execution.
After that, attack the four remaining cyborgs to recharge your gauge, and immediately Blade Mode them (trying to get multiple enemies at once).
Be quick! It took me a long time to get top score on that one, but it's definitely doable. The trick is taking down the Gekko quickly.
Edit: Also, do NOT Zandatsu (press the Circle to rip out the spine). It carves off precious seconds that you do not have to spare. There are other, faster methods of refueling your gauge. Just don't swing around wildly in Blade Mode, and a few normal attacks will fill you back up.