I’m not sure what “levels fats” means here, but in Combat Initiation the usual way to level up or progress is to keep clearing waves, stay alive, and use upgrades between rounds. The beginner guides describe a simple loop: start in a lobby, pick your weapons, dodge aggressively, focus on gun enemies fast, and keep eliminating enemies to reach higher rank at the end of each stage.

What to do

  • Play in a small or empty lobby first so it’s easier to learn the wave patterns.
  • Pick a reliable starter setup, like Sword or Slingshot with a strong secondary.
  • Prioritize enemies with guns as soon as they spawn, because they can drop your HP quickly.
  • Use double-jumps and pounces to dodge, since mobility is key and stamina refills quickly.
  • Keep upgrading weapons as you progress through stages to improve your run.

If you meant something else

If “fats” was a typo for fast , the fastest path is basically to survive longer, clear waves efficiently, and learn enemy timing rather than rushing in. If you meant a specific stat, badge, or in-game currency, that would need a different answer because Combat Initiation guides mostly talk about wave survival and weapon upgrades rather than a “fat” level system.

TL;DR

There doesn’t appear to be a special “fats” leveling mechanic in Combat Initiation; progression is mainly about clearing waves, dodging well, and upgrading weapons between rounds.