head to head
Neither is simply harder - they are hard in different places. Super Smash Bros. Melee demands more execution; Worms 3D demands more variance.

Execution · Competitive PvP
A platform fighter with one of the highest execution ceilings in any competitive game, layered on top of deep human reads.

Execution · Competitive PvP
Artillery touch, human prediction and weapon economy in destructible 3D terrain.
Super Smash Bros. Melee leans Execution (Competitive PvP); Worms 3D leans Execution (Competitive PvP).
Super Smash Bros. Melee leans clearly harder on execution.
Super Smash Bros. Melee
Wavedashing, L-cancels, and tech-chasing set an extreme physical ceiling
Worms 3D
Judging grenade arcs and wind in 3D takes real touch
Super Smash Bros. Melee leans clearly harder on reads.
Super Smash Bros. Melee
Reading DI choices and opponent adaptive habits is constant and non-convergent
Worms 3D
Predicting where a human hides and strikes next matters
Worms 3D leans clearly harder on variance.
Super Smash Bros. Melee
Stage hazard RNG and spawn positions add marginal chaos
Worms 3D
Wind, crate drops and terrain chaos swing turns
Super Smash Bros. Melee leans a little harder on optimization, though the gap is small.
Super Smash Bros. Melee
Character matchup tiers and optimal movement routing are deeply studied
Worms 3D
Weapon economy and positioning math reward planning
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.