How to rank up in perfect dark
I've investigated more about this question. It seems you start at rank 21 and go down to 1. Seems backwards in today's video game industry.
Since you asked how to get to level 1 (Perfection rank), here are the requirements I found on another website:
Kills: 18,000
Damage Dealt: 180,000
Ammo Used: 450,000
Distance: 9000 km
Time: 12:12:00 (12 days, 12 hours, 0 minutes)
Games Won: 900
Accuracy Medals: 900
Head Shot Medals: 900
Killmaster Medals: 900
Survivor Medals: 900
Goodluck! Seems like it will take a while.