head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Light / Casual
A comedy sandbox testing nothing harder than enthusiasm for collateral damage.

Execution · Practiced Mastery
An early top-down rampage shooter with simple execution demands.
Kill It With Fire leans Execution (Light / Casual); Postal leans Execution (Practiced Mastery).
Postal leans a little harder on execution, though the gap is small.
Kill It With Fire
Swatting spiders needs only loose aim
Postal
top-down shooting and movement
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Kill It With Fire
Spiders scuttle on simple RNG, no minds here
Postal
enemies use fixed aggressive scripts
Kill It With Fire leans a little harder on variance, though the gap is small.
Kill It With Fire
Spider hiding spots are unknown until flushed out
Postal
enemy spawn and pathing randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Kill It With Fire
Checklist objectives and weapon unlocks, deliberately shallow
Postal
weapon choice and route clearing
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.