head to head
Tower of Guns asks more than Half-Life 2, and the gap is variance.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.

Execution · Pure Mechanics
A fast bullet-hell first-person shooter built for short randomised lunch-break runs.
Half-Life 2 leans Execution (Pure Mechanics); Tower of Guns leans Execution (Pure Mechanics).
Tower of Guns leans clearly harder on execution.
Half-Life 2
Gravity gun and shooting demand precision.
Tower of Guns
Dodging bullet storms and aiming carries the whole game
Half-Life 2 leans a little harder on reads, though the gap is small.
Half-Life 2
Combine AI scripted, non-adaptive.
Tower of Guns
Turrets follow fixed scripts, no adaptive opposition
Tower of Guns leans clearly harder on variance.
Half-Life 2
Almost no randomness.
Tower of Guns
Randomised rooms, guns and perks each run
Tower of Guns leans a little harder on optimization, though the gap is small.
Half-Life 2
Linear progression with no builds.
Tower of Guns
Gun levelling and secret routes reward 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.