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

Execution · Practiced Mastery
Slow-weapon stealth shooting wrapped around hidden-clue investigation.

Execution · Practiced Mastery
Claustrophobic post-apocalyptic shooter where bullets double as currency.
Betrayer leans Execution (Practiced Mastery); Metro 2033 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Betrayer
Slow musket shots make each aimed round count
Metro 2033
scarce-ammo gunfights punish sloppy aim
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Betrayer
Ghostly foes patrol on scripts
Metro 2033
mutants and bandits follow scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Betrayer
Clue locations and ambushes are hidden until found
Metro 2033
hidden moral points and supplies first run
Metro 2033 leans a little harder on optimization, though the gap is small.
Betrayer
Mystery-piecing and loadout choices reward methodical play
Metro 2033
ammo-as-currency economy and stealth routing
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.