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 · Pure Optimization
A Hitman-style Cold War stealth game about a KGB assassin working sandboxed kill missions.

Optimization · Pure Optimization
Side-on turn-based tactics where you manually aim ricocheting bullets for a steambot pirate crew.
Alekhine's Gun leans Optimization (Pure Optimization); SteamWorld Heist 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.
Alekhine's Gun
Timing takedowns matters less than planning them
SteamWorld Heist
Manual aim and ricochet shots reward steady hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Alekhine's Gun
NPC routines are clockwork, never reactive learning
SteamWorld Heist
Enemy bots follow fixed behaviors
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Alekhine's Gun
First visits hide patrol routines and disguise rules
SteamWorld Heist
Procedural ship layouts and loot drops
Alekhine's Gun leans a little harder on optimization, though the gap is small.
Alekhine's Gun
Mapping routines and disguises reduces missions to solved puzzles
SteamWorld Heist
Crew builds, weapon picks, and turn routing carry runs
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.