head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Practiced Mastery
A gritty WWII Call of Duty that introduced the Zombies mode.

Execution · Practiced Mastery
A brawler that tests combo execution and crowd management across linear gauntlets, with a light optimisation layer from its RPG progression.
Call of Duty: World at War leans Execution (Practiced Mastery); Castle Crashers leans Execution (Practiced Mastery).
Call of Duty: World at War leans a little harder on execution, though the gap is small.
Call of Duty: World at War
Twitch gunfights in fast multiplayer lobbies
Castle Crashers
Combo execution and crowd-control timing are the performance ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Human opponents reward positioning prediction
Castle Crashers
PvP arenas add light human-opponent reads
Call of Duty: World at War leans a little harder on variance, though the gap is small.
Call of Duty: World at War
Random lobbies, spawns, and zombie waves
Castle Crashers
Enemy spawns follow scripted patterns with minimal randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Perk loadouts and map control are learnable
Castle Crashers
Levelling investment, magic loadout, and pet choice are optimisable
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.