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
A one-hit boss-rush where solving each titan still demands perfect execution.

Execution · Practiced Mastery
Combo execution and line routing through fixed skateparks for maximum score.
Titan Souls leans Execution (Practiced Mastery); Tony Hawk's Proving Ground 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.
Titan Souls
One arrow, one hit point; every shot must be perfect
Tony Hawk's Proving Ground
Perfect inputs chain manuals, grinds and Nail-the-Trick combos indefinitely
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Titan Souls
Bosses are scripted patterns, not adaptive minds
Tony Hawk's Proving Ground
Multiplayer score battles barely involve predicting opponents
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Titan Souls
Unknown boss gimmicks only on first attempts
Tony Hawk's Proving Ground
Skateparks are fixed and fully learnable
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Titan Souls
Each titan has a solvable weak-point strategy
Tony Hawk's Proving Ground
Routing the highest-scoring combo line through terrain is the meta
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.