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 · Practiced Mastery
The sequel adding Horde mode to the campaign-plus-versus cover shooter formula.

Execution · Competitive PvP
A wrestling fighting game about timing grapples and reading opponents.
Gears of War 2 leans Execution (Practiced Mastery); Rumble Roses XX leans Execution (Competitive PvP).
Gears of War 2 leans a little harder on execution, though the gap is small.
Gears of War 2
Gnasher battles and movement tech set the ceiling
Rumble Roses XX
Grapple timing and counters demand precise input
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 2
Human opponents in versus drive prediction play
Rumble Roses XX
Human opponents require reading attack and grapple timing
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 2
Horde spawns add mild randomness
Rumble Roses XX
Some reversal and grapple randomness
Gears of War 2 leans a little harder on optimization, though the gap is small.
Gears of War 2
Power-weapon timing and positioning are solvable
Rumble Roses XX
Move sets and match strategy reward planning
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.