head to head
Neither is simply harder - they are hard in different places. DOOM (2016) demands more optimization; Micro Machines V3 demands more reads.

Execution · Pure Mechanics
Push-forward arena FPS where movement and aim are the whole game.

Execution · Pure Mechanics
Tests twitchy miniature car control and track memory amid party-weapon chaos.
DOOM (2016) leans Execution (Pure Mechanics); Micro Machines V3 leans Execution (Pure Mechanics).
DOOM (2016) leans a little harder on execution, though the gap is small.
DOOM (2016)
Aim, movement, glory-kill timing all peak.
Micro Machines V3
Tiny cars on twisty tabletops punish every slip
Micro Machines V3 leans clearly harder on reads.
DOOM (2016)
Demons scripted attack patterns.
Micro Machines V3
Couch rivals can be baited with weapons and nudges
Micro Machines V3 leans clearly harder on variance.
DOOM (2016)
Minimal encounter randomness.
Micro Machines V3
Pickup spawns and chaos shuffle close races
DOOM (2016) leans clearly harder on optimization.
DOOM (2016)
Rune and weapon mod picks meaningful.
Micro Machines V3
Track memorisation and shortcut lines pay off
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.