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 · Twitch Chaos
Co-op zombie shooter whose AI Director reshuffles every run to keep teams honest.

Execution · Practiced Mastery
A falling-block puzzle testing fast coin-combining under accelerating speed.
Left 4 Dead leans Execution (Twitch Chaos); Money Puzzle Exchanger 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.
Left 4 Dead
Headshots, melee shoves, and special-infected reaction time
Money Puzzle Exchanger
Fast coin manipulation under accelerating speed
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Left 4 Dead
Versus mode adds human ambush mindgames
Money Puzzle Exchanger
Versus play adds light pressure, no deep modeling
Left 4 Dead leans a little harder on variance, though the gap is small.
Left 4 Dead
AI Director randomizes hordes, items, and specials
Money Puzzle Exchanger
Falling coin order is bounded randomness
Money Puzzle Exchanger leans a little harder on optimization, though the gap is small.
Left 4 Dead
Team spacing, route choice, and resource discipline
Money Puzzle Exchanger
Chaining exchanges optimally is the scoring core
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.