Building comparison
head to head
Left 4 DeadvsSpelunky
Spelunky asks more than Left 4 Dead, and the gap is variance.
Left 4 Dead
Execution · Twitch Chaos
Co-op zombie shooter whose AI Director reshuffles every run to keep teams honest.
Spelunky
Execution · Twitch Chaos
The original procedural platformer that codified the modern roguelike action loop.
Left 4 Dead leans Execution (Twitch Chaos); Spelunky leans Execution (Twitch Chaos).
Left 4 DeadSpelunky
Axis by axis
Execution7 vs 8
Spelunky leans a little harder on execution, though the gap is small.
Left 4 Dead
Headshots, melee shoves, and special-infected reaction time
Spelunky
Tight platforming and whip control under constant threat.
Reads2 vs 1
Left 4 Dead leans a little harder on reads, though the gap is small.
Left 4 Dead
Versus mode adds human ambush mindgames
Spelunky
Enemy AI is scripted; no adaptive opponents.
Variance5 vs 7
Spelunky leans clearly harder on variance.
Left 4 Dead
AI Director randomizes hordes, items, and specials
Spelunky
Procedural caves and item rolls shape every run.
Optimization5 vs 6
Spelunky leans a little harder on optimization, though the gap is small.
Left 4 Dead
Team spacing, route choice, and resource discipline
Spelunky
Hell route and shortcuts reward solved knowledge.
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.