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

Execution · Practiced Mastery
Precision sniping and arena navigation through fixed, gimmick-laden levels.

Execution · Pure Mechanics
An on-rails aim-and-memorise test through fixed FMV sequences.
MDK leans Execution (Practiced Mastery); Star Wars: Rebel Assault 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.
MDK
Sniper-mode precision and arena dodging demand steady hands
Star Wars: Rebel Assault
On-rails aiming and dodge timing is the entire challenge
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
MDK
Alien enemies behave on fixed scripts
Star Wars: Rebel Assault
Every sequence is pre-rendered and fixed
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
MDK
Levels are authored with nothing random
Star Wars: Rebel Assault
Nothing varies between attempts
MDK leans a little harder on optimization, though the gap is small.
MDK
Learning arena gimmicks and item use solves each level
Star Wars: Rebel Assault
Memorising each rail sequence's threats carries completion
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.