head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Sandbox FPS where a nanosuit lets you choose speed, strength, or stealth per fight.

Execution · Practiced Mastery
Mars-mining rebellion FPS famous for letting you blast through the terrain itself.
Crysis leans Execution (Practiced Mastery); Red Faction 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.
Crysis
gunplay and suit-mode switching mid-fight
Red Faction
Classic FPS aim and movement carry the campaign.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Crysis
AI soldiers are scripted searchers
Red Faction
Scripted guards; multiplayer was a minor side mode.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Crysis
open encounters play out unpredictably at first
Red Faction
Unknown level layouts first time through.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Crysis
suit energy management and approach planning
Red Faction
Geo-Mod tunneling and route knowledge open solvable shortcuts.
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.