head to head
Neither is simply harder - they are hard in different places. Just Act Natural demands more reads; Nintendo Land demands more execution.

Reads · Pure Mind Games
Behavioural bluffing - mimicking NPCs while human seekers learn your tells.

Execution · Competitive PvP
Wii U minigame park whose asymmetric hide-and-seek modes shine with friends.
Just Act Natural leans Reads (Pure Mind Games); Nintendo Land leans Execution (Competitive PvP).
Nintendo Land leans clearly harder on execution.
Just Act Natural
Walking like an NPC needs restraint, not dexterity
Nintendo Land
Motion and GamePad dexterity across minigames
Just Act Natural leans clearly harder on reads.
Just Act Natural
Out-guessing human seekers and hiders is the whole game
Nintendo Land
Asymmetric chase games create real human mind-games
Just Act Natural leans a little harder on variance, though the gap is small.
Just Act Natural
NPC crowds and tasks add cover noise
Nintendo Land
Some random layouts and item spawns
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Just Act Natural
Task patterns can be learned but humans counter-adapt
Nintendo Land
Per-attraction tactics, mostly shallow
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.