head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Practiced Mastery
Steady aim against scripted alien swarms with an upgrade economy underneath.

Execution · Practiced Mastery
Retro ninja platformer that flips from linear levels into a time-hopping metroidvania.
Alien Breed: Impact leans Execution (Practiced Mastery); The Messenger leans Execution (Practiced Mastery).
The Messenger leans a little harder on execution, though the gap is small.
Alien Breed: Impact
Kiting alien swarms top-down demands steady aim and movement
The Messenger
cloudstep chains demand precise aerial control
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed: Impact
Aliens swarm on scripts, never modelling you
The Messenger
enemies and bosses are fully scripted
Alien Breed: Impact leans a little harder on variance, though the gap is small.
Alien Breed: Impact
Ambush triggers are scripted-but-unknown first time through
The Messenger
deterministic level design
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Breed: Impact
Weapon upgrades and ammo economy reward planning
The Messenger
upgrade economy and late-game route 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.