head to head
Fire Emblem Fates asks more than Portal 2, and the gap is variance.

Optimization · Pure Optimization
Optimizing pair-up chains and offspring builds to steamroll deterministically scripted maps.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Fire Emblem Fates leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans a little harder on execution, though the gap is small.
Fire Emblem Fates
Turn-based menu play; no hand-speed demands
Portal 2
Portal placement requires some precision but timing is lenient.
Fire Emblem Fates leans a little harder on reads, though the gap is small.
Fire Emblem Fates
AI follows scripted attack priorities, not player modeling
Portal 2
No opponent; puzzles are static.
Fire Emblem Fates leans clearly harder on variance.
Fire Emblem Fates
Dual-strike/guard procs and hit rates inject meaningful RNG
Portal 2
Puzzles are deterministic with no randomness.
Portal 2 leans a little harder on optimization, though the gap is small.
Fire Emblem Fates
Offspring seals, asset/flaw selection, and supports are deeply planned
Portal 2
Solving the puzzle's logic IS the entire game.
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.