head to head
Neither is simply harder - they are hard in different places. Hidden in Plain Sight demands more reads; Super Smash Bros. Brawl demands more execution.

Reads · Pure Mind Games
A couch party game where players imitate AI characters and try to spot which sprites are human.

Reads · Competitive PvP
The Wii entry whose slower pace and infamous random tripping pushed Smash toward defensive mind games.
Hidden in Plain Sight leans Reads (Pure Mind Games); Super Smash Bros. Brawl leans Reads (Competitive PvP).
Super Smash Bros. Brawl leans clearly harder on execution.
Hidden in Plain Sight
Simple inputs; a steady trigger finger helps slightly.
Super Smash Bros. Brawl
Slower engine lowers the ceiling but spacing still needs hands.
Hidden in Plain Sight leans clearly harder on reads.
Hidden in Plain Sight
Acting like an NPC against watching humans is the entire game.
Super Smash Bros. Brawl
Defensive bait-and-punish yomi dominates its floaty neutral.
Hidden in Plain Sight leans a little harder on variance, though the gap is small.
Hidden in Plain Sight
NPC crowds and random objectives provide cover noise.
Super Smash Bros. Brawl
Random tripping injects genuine uncontrollable RNG into movement.
Super Smash Bros. Brawl leans clearly harder on optimization.
Hidden in Plain Sight
Minimal systems; little to optimize beyond NPC mimicry.
Super Smash Bros. Brawl
Matchup knowledge and ledge play reward study within a campy 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.