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

Optimization · Pure Optimization
The Wii and PSP entry reworking Tenchu into deliberate puzzle-flavored shadow stealth.

Optimization · Pure Optimization
Definitive top-down Zelda spanning light and dark mirrored worlds.
Tenchu: Shadow Assassins leans Optimization (Pure Optimization); The Legend of Zelda: A Link to the Past leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Tenchu: Shadow Assassins
Simplified controls shift weight off raw dexterity
The Legend of Zelda: A Link to the Past
Responsive combat and boss dodging, moderate demand
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Tenchu: Shadow Assassins
Guards follow rigid scripted vision cones
The Legend of Zelda: A Link to the Past
All enemies scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Tenchu: Shadow Assassins
Little randomness once a level is scouted
The Legend of Zelda: A Link to the Past
Secrets unknown until found
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Tenchu: Shadow Assassins
Shadow paths and tool use make missions puzzle-like
The Legend of Zelda: A Link to the Past
Two-world puzzle structure and item-driven 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.