head to head
Call of Duty: Modern Warfare 2 asks more than Worms Rumble, and the gap is optimization.

Execution · Competitive PvP
Blockbuster 2009 sequel famous for killstreak chains and frantic multiplayer.

Execution · Competitive PvP
Real-time arena aim duels against human worms with randomised weapon pickups.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); Worms Rumble leans Execution (Competitive PvP).
Call of Duty: Modern Warfare 2 leans a little harder on execution, though the gap is small.
Call of Duty: Modern Warfare 2
Fast time-to-kill rewards raw aim and reflex
Worms Rumble
Real-time aim and movement decide brawls, unlike turn-based Worms
Call of Duty: Modern Warfare 2 leans a little harder on reads, though the gap is small.
Call of Duty: Modern Warfare 2
Outguessing human rotations and flanks
Worms Rumble
Human opponents in arena and royale modes can be predicted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Modern Warfare 2
Spawn flips and killstreak randomness
Worms Rumble
Weapon crate spawns and drop positions add randomness
Call of Duty: Modern Warfare 2 leans clearly harder on optimization.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
Worms Rumble
Loadout knowledge and map control matter but stay shallow
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.