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 · Practiced Mastery
A Tetris variant testing placement speed with a square-building scoring layer.
Painkiller (2004) leans Execution (Pure Mechanics); The New Tetris leans Execution (Practiced Mastery).
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
The New Tetris
Fast precise placement under speed is the lead axis
The New Tetris leans a little harder on reads, though the gap is small.
Painkiller (2004)
All enemies are scripted waves with fixed attack patterns
The New Tetris
Multiplayer adds light prediction, 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
The New Tetris
Piece bag is random but bounded and mappable
The New Tetris leans a little harder on optimization, though the gap is small.
Painkiller (2004)
Tarot card selection and level routing provide a thin solvable layer
The New Tetris
Building 4x4 squares for bonus rewards deeper strategy
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.