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
Side-on turn-based tactics where you manually aim ricocheting bullets for a steambot pirate crew.

Optimization · Pure Optimization
A 2D sandbox where preparation and gear tiering carry boss fights.
SteamWorld Heist leans Optimization (Pure Optimization); Terraria 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.
SteamWorld Heist
Manual aim and ricochet shots reward steady hands
Terraria
Boss fights require dodging and aim under pressure.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
SteamWorld Heist
Enemy bots follow fixed behaviors
Terraria
Bosses use scripted attacks; no adaptation.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
SteamWorld Heist
Procedural ship layouts and loot drops
Terraria
World seeds and loot drops randomized.
Terraria leans a little harder on optimization, though the gap is small.
SteamWorld Heist
Crew builds, weapon picks, and turn routing carry runs
Terraria
Gear progression and arena prep solve every boss.
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.