head to head
Left 4 Dead asks more than City of Brass, and the gap is reads.

Execution · Twitch Chaos
An Arabian Nights first-person roguelite about whipping enemies into the city's own traps.

Execution · Twitch Chaos
Co-op zombie shooter whose AI Director reshuffles every run to keep teams honest.
City of Brass leans Execution (Twitch Chaos); Left 4 Dead leans Execution (Twitch Chaos).
Left 4 Dead leans a little harder on execution, though the gap is small.
City of Brass
Whip-and-sword timing against traps demands reflexes
Left 4 Dead
Headshots, melee shoves, and special-infected reaction time
Left 4 Dead leans clearly harder on reads.
City of Brass
Enemies and traps are scripted
Left 4 Dead
Versus mode adds human ambush mindgames
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
City of Brass
Procedural streets, relics, and genie wares vary runs
Left 4 Dead
AI Director randomizes hordes, items, and specials
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
City of Brass
Trap manipulation and treasure routing reward learned play
Left 4 Dead
Team spacing, route choice, and resource discipline
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.