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

Execution · Pure Mechanics
Linear military FPS about resisting an occupation of the United States.

Execution · Pure Mechanics
Motion-controlled tennis, bowling, golf, baseball and boxing built around simple swing gestures.
Homefront leans Execution (Pure Mechanics); Wii Sports leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Homefront
Standard shooter gunplay carries the campaign
Wii Sports
Motion swing timing and accuracy decide every event
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Homefront
Multiplayer adds some human prediction
Wii Sports
Casual local opponents add light mind games
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Homefront
Scripted setpieces, little randomness
Wii Sports
Minor physics wobble and CPU behaviour randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Homefront
Modest loadout and map knowledge layer
Wii Sports
Simple technique tricks like bowling spin are learnable
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.