First we have to enter the Cat Base screen, then the player will find a shopping cart looking icon at the bottom of this screen in Cat Base.

After entering the Meow Wars store interface, we swipe to the right to see the XP selling price, and players can purchase the amount of XP they can buy based on their cat food.

The acquired cats can be upgraded with the experience value (XP) to strengthen the cat's ability.

After passing the second chapter of the world chapter, all cats can be upgraded to the 20th level using XP; the upgrade limit of different cats can be liberated separately when reaching a specific level ranking.

When passing the total level ranking of 1600, the system will release the "Cat's Eye Stone" function (you can get the Cat's Eye Stone from the Plus Code Duo adventure or the level ranking rewards). When some of the Ex level, rare level or above cats reach the level cap of 30, the Cat's Eye Stone can be used to raise the level cap of the cat by one level; after passing all the 1-star legendary levels, the number of Cat's Eye Stones to release the level cap of the cat can be increased.

All cats will change their appearance at level 10, which is called "Evolution 2", and at level 30, they will get "Evolution 3". The basic cats can evolve directly; some legendary level cats and some rare eggs require "catnip"; some EX cats, wheel cats and small cats purchased with cat cans need to pass the eye opening level; the frenzy series needs to pass the "Great Frenzy" level; the storm family cats and the extremely difficult series cats need to pass the "Whirlwind of Strikes" or "Extreme Difficulties of Strikes" level.

Each evolution will improve the cat's combat power or unlock the ability to target attributes.

After passing the third chapter of the future chapter, you can use "NP" to open the special ability of the cat (currently can only be exchanged through the cat in the storage library) or target attributes and strengthen the basic body and resistance to enemy effects.