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

Execution · Pure Mechanics
Raw arcade reflexes against accelerating swarms with mild spawn randomness.

Execution · Pure Mechanics
Rapid-fire recognition and reaction across hundreds of five-second microgames.
Millipede leans Execution (Pure Mechanics); WarioWare, Inc.: Mega Microgame$! leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Millipede
Trackball precision under swarming pressure is everything
WarioWare, Inc.: Mega Microgame$!
Reacting correctly in five-second microgames is the entire challenge
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Millipede
Enemies follow fixed movement rules
WarioWare, Inc.: Mega Microgame$!
No adaptive opponent - microgames are scripted
WarioWare, Inc.: Mega Microgame$! leans a little harder on variance, though the gap is small.
Millipede
Spawn waves and DDT timing vary run to run
WarioWare, Inc.: Mega Microgame$!
Random microgame order forces instant recognition each round
Millipede leans a little harder on optimization, though the gap is small.
Millipede
Mushroom-field management is a thin strategic layer
WarioWare, Inc.: Mega Microgame$!
Each microgame's solution is trivial once seen
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.