head to head
Neither is simply harder - they are hard in different places. Evil demands more execution; Marbles on Stream demands more variance.

Variance · Systems & Chaos
A short first-person horror game testing nerve against scripted home invasion scares.

Variance · Pure Chaos
Tests nothing but luck - a spectator marble race decided entirely by physics RNG.
Evil leans Variance (Systems & Chaos); Marbles on Stream leans Variance (Pure Chaos).
Evil leans clearly harder on execution.
Evil
Walking and looking; minimal physical demand
Marbles on Stream
You watch a marble roll; no inputs matter
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Evil
Scare events are scripted, not an adaptive mind
Marbles on Stream
No opponent decisions exist to predict
Marbles on Stream leans clearly harder on variance.
Evil
Hidden scares and events drive the unknown tension
Marbles on Stream
Physics RNG decides the entire race outcome
Evil leans clearly harder on optimization.
Evil
Figuring out what to do next is the small loop
Marbles on Stream
Nothing to solve beyond picking a marble skin
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.