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

Execution · Pure Mechanics
A test of fast, precise shooting and map navigation against scripted but relentless enemies.

Execution · Pure Mechanics
A marble-shooting puzzle where you match colours before the chain reaches the skull.
Doom (1993) leans Execution (Pure Mechanics); Zuma leans Execution (Pure Mechanics).
Doom (1993) leans a little harder on execution, though the gap is small.
Doom (1993)
Precise movement and shooting against relentless enemy pressure
Zuma
Fast accurate shots under chain pressure
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Doom (1993)
Enemies follow scripted patrol and attack patterns, not adaptive
Zuma
No adaptive opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Doom (1993)
Enemy placement is fixed but unknown on first run through levels
Zuma
Ball colour feed is random
Doom (1993) leans a little harder on optimization, though the gap is small.
Doom (1993)
Level routing and resource management determine survival efficiency
Zuma
Chain setups, gap shots, combo planning
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.