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.

Optimization · Pure Optimization
Lane defense classic about managing a sun economy against shambling waves.

Optimization · Pure Optimization
Optimizing mecha squad builds and development plans through solvable tactical stages.
Plants vs. Zombies leans Optimization (Pure Optimization); SD Gundam G Generation Cross Rays leans Optimization (Pure Optimization).
Plants vs. Zombies leans a little harder on execution, though the gap is small.
Plants vs. Zombies
Clicking to plant, minimal pressure
SD Gundam G Generation Cross Rays
Turn-based menus - hands are irrelevant
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Plants vs. Zombies
Zombie waves follow set compositions
SD Gundam G Generation Cross Rays
Enemy AI follows fixed priorities, never models you
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Plants vs. Zombies
Wave timing and lane pressure vary mildly
SD Gundam G Generation Cross Rays
Hit rolls and crits wobble individual turns slightly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Plants vs. Zombies
Sun economy and lane setups are near-solvable
SD Gundam G Generation Cross Rays
Squad building, unit development and stage routing is the game
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.