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.

Optimization · Systems & Chaos
Deduce hidden words and manage letter resources through a dungeon of wordplay.

Optimization · Pure Optimization
A 2D sandbox of procedurally generated planets driven by crafting progression.
Cryptmaster leans Optimization (Systems & Chaos); Starbound leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Cryptmaster
Typing words quickly under combat pressure matters somewhat
Starbound
Light platforming and combat, generous margins
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cryptmaster
The Cryptmaster narrates a script, not an adapting mind
Starbound
Procedural NPCs follow simple fixed behaviours
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Cryptmaster
Hidden letters and unknown answers drive the guessing
Starbound
Procedural planets and loot keep early exploration unknown
Starbound leans a little harder on optimization, though the gap is small.
Cryptmaster
Vocabulary deduction and ability management are the solvable core
Starbound
Gear tiers, farming, and progression routes dominate
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.