head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Competitive PvP
Arcade tennis with timing-based PvP mind games.

Execution · Pure Mechanics
Physics hockey where manual stick control and outplaying humans decide everything.
Mario Tennis Aces leans Execution (Competitive PvP); Slapshot: Rebound leans Execution (Pure Mechanics).
Slapshot: Rebound leans a little harder on execution, though the gap is small.
Mario Tennis Aces
Shot timing, charge mechanics, footwork
Slapshot: Rebound
Manual stick rotation makes every pass and shot a motor test
Mario Tennis Aces leans a little harder on reads, though the gap is small.
Mario Tennis Aces
Online tennis demands reading opponent placement
Slapshot: Rebound
Human defenders force constant deking and anticipation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Tennis Aces
Mostly deterministic ball physics
Slapshot: Rebound
Pure physics, explicitly no RNG by design
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Tennis Aces
Character matchups and tech routes
Slapshot: Rebound
Team positioning and rotations matter but stay simple
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.