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.

Optimization · Light / Casual
Cyberpunk horror where a detective hacks the memories of the dying.
Kill It With Fire leans Execution (Light / Casual); Observer leans Optimization (Light / Casual).
Kill It With Fire leans a little harder on execution, though the gap is small.
Kill It With Fire
Swatting spiders needs only loose aim
Observer
Walking with brief stealth segments
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
Observer
The stalker sequence is scripted
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
Observer
Unknown story branches and apartment secrets
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
Observer
Investigation logic and clue piecing
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.