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 blistering DS Sonic built around the boost gauge, introducing Blaze the Cat.

Execution · Practiced Mastery
Sonic alternates breakneck daytime boost stages with brawling night levels as the Werehog.
Sonic Rush leans Execution (Practiced Mastery); Sonic Unleashed 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.
Sonic Rush
Boost management and trick timing at high speed
Sonic Unleashed
Daytime boost stages demand reaction-speed precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic Rush
Scripted bosses only
Sonic Unleashed
Scripted enemies in both forms
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic Rush
Dual-screen layouts surprise on first runs
Sonic Unleashed
First-run stage hazards arrive fast and unseen
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic Rush
Rank grinding turns levels into solved boost routes
Sonic Unleashed
S-rank routes and Werehog combat upgrades are solvable
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.