In Lies of P killing enemies grants Ergo which is synonymous with XP in other games. While Ergo is also a currency used for purchasing items from vendors, you can actually put it towards player attributes in order to level up. This Lies of P guide will walk you through good Ergo runs to go on, in order to level up faster.
P-Organ Upgrade
Before you begin farming, it is recommended that you unlock the Phase 1 upgrade “Increases Ergo upon eliminating an enemy 1”, under the Item Type tab. Once activated, this upgrade will grant you a 10% bonus each time you earn Ergo.
Krat City Hall
This early Ergo farm has you starting from the Stargazer, where you have a conga line of relatively weak guard puppets worth 90 Ergo each. They are also susceptible to backstab attacks for quicker takedowns. Make your way through the streets and up the stairs into the building to complete the run. You will encounter a total of seven guard puppets and a single dog puppet worth 32 Ergo. Teleport back to the Stargazer to respawn and repeat.
This ninety second run is worth a total of 662 Ergo, plus 10% Ergo bonus with the P-Organ upgrade, and the additional value of any loot.
Workshop Union Entrance
Begin at the Stargazer, and enter the door that is right there and quickly dispatch two mannequins for 115 Ergo a piece. Head back outside to the Stargazer, then Make your way around the corner to the alley with the two mannequins lying in ambush, and the larger puppet whaling on a corpse. Dispatch the mannequins first to get them out of the way, then quickly stagger and terminate the big enemy for 353 Ergo, and which will also drop a Star Fragment almost every time. All three will often drop Hidden Moonstones, Ergo Fragments, and Sawtoothed Wheels, among other items. Rinse and repeat by either teleporting or sprinting back to the Stargazer.
This run is worth 813 Ergo each time, plus 10% Ergo bonus with the P-Organ upgrade, and the value of potential loot drops added on top of that. Completion time is less than a minute, start to finish.
Those are two early game avenues to gain Ergo quickly and level up fast in Lies of P.