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
Classic Tetris execution under audiovisual flow, speed still decides everything.

Execution · Pure Mechanics
Final Fantasy music rhythm game layering light RPG party building over note charts.
Tetris Effect leans Execution (Pure Mechanics); Theatrhythm Final Bar Line 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.
Tetris Effect
Piece placement under speed and Zone timing is the whole test
Theatrhythm Final Bar Line
Note timing accuracy on Ultimate charts
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Tetris Effect
Solo experience with no opponent to model
Theatrhythm Final Bar Line
Fixed charts, no opponent
Tetris Effect leans a little harder on variance, though the gap is small.
Tetris Effect
Randomised bag is bounded and quickly mappable
Theatrhythm Final Bar Line
Quest drops are random, gameplay is deterministic
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Tetris Effect
Stacking theory and Zone usage have known optimal lines
Theatrhythm Final Bar Line
Party builds and abilities optimize quest clears
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.