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

Optimization · Pure Optimization
A tower defense game about engineering optimal gem combinations against scripted waves.

Optimization · Pure Optimization
Grand strategy wargame mixing turn-based empire play with real-time battles.
GemCraft leans Optimization (Pure Optimization); Medieval II: Total War leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
GemCraft
Placing gems and towers has no twitch demand
Medieval II: Total War
real-time battle micro is modest
Medieval II: Total War leans a little harder on reads, though the gap is small.
GemCraft
Monster waves are scripted, never adapting to player
Medieval II: Total War
campaign AI is exploitable and mappable
Medieval II: Total War leans a little harder on variance, though the gap is small.
GemCraft
Wave composition is fixed once a level is known
Medieval II: Total War
fog of war and event triggers hide some state
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
GemCraft
Combining gems for optimal tower output is the entire game
Medieval II: Total War
economy, unit counters, and campaign map strategy dominate
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.