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

Optimization · Practiced Mastery
An open-world pirate adventure where upgrading the Jackdaw matters more than the blade.

Optimization · Practiced Mastery
Tim Schafer's heavy-metal open world that morphs into RTS-style stage battles.
Assassin's Creed IV: Black Flag leans Optimization (Practiced Mastery); Brütal Legend leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed IV: Black Flag
Naval broadsides and boarding need modest timing
Brütal Legend
Hack-and-slash combat is forgiving
Brütal Legend leans a little harder on reads, though the gap is small.
Assassin's Creed IV: Black Flag
Multiplayer deception mode; campaign is scripted
Brütal Legend
Multiplayer stage battles pit you against adapting commanders
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed IV: Black Flag
Weather, convoys, and hunting spawns
Brütal Legend
Unit skirmish chaos adds noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed IV: Black Flag
Ship upgrades and fleet economy drive progress
Brütal Legend
Stage-battle economy and unit counters reward strategy
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.