head to head
Neither is simply harder - they are hard in different places. Nidhogg demands more execution; Thief Town demands more variance.

Reads · Competitive PvP
Minimalist fencing duel that is almost entirely about out-guessing one human.

Reads · Pure Mind Games
A local-multiplayer stealth game about blending in and reading which figures are human.
Nidhogg leans Reads (Competitive PvP); Thief Town leans Reads (Pure Mind Games).
Nidhogg leans clearly harder on execution.
Nidhogg
Sword-height changes and dive-kicks need quick hands
Thief Town
Timed stab inputs matter but aren't the ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Nidhogg
Pure human duels of feints and conditioning
Thief Town
Reading human players hiding among NPCs is the core
Thief Town leans clearly harder on variance.
Nidhogg
Symmetric deterministic arenas
Thief Town
Crowd of identical NPCs hides players, adding uncertainty
Nidhogg leans a little harder on optimization, though the gap is small.
Nidhogg
Small toolkit, little to solve beyond fundamentals
Thief Town
Little system to solve beyond the bluffing layer
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.