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

Execution · Pure Mechanics
A relentless wave-clearing shooter that tests sustained aim and movement against massive scripted enemy crowds.

Execution · Pure Mechanics
A Tetris variant testing piece-placement speed with multiple ruleset modes.
Painkiller (2004) leans Execution (Pure Mechanics); Tetris Worlds 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.
Painkiller (2004)
Constant crowd-control movement against overwhelming enemy counts demands fast aim
Tetris Worlds
Fast precise piece placement under speed is the lead
Tetris Worlds leans a little harder on reads, though the gap is small.
Painkiller (2004)
All enemies are scripted waves with fixed attack patterns
Tetris Worlds
Multiplayer adds light prediction but mostly solo speed
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Painkiller (2004)
Enemy counts and placements are fixed with minimal unknown elements
Tetris Worlds
Piece bag is random but bounded and mappable
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Painkiller (2004)
Tarot card selection and level routing provide a thin solvable layer
Tetris Worlds
Stacking strategies have known optimal patterns
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.