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

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

Optimization · Pure Optimization
A drug-empire logistics puzzle - recipes, pricing and supply chains to optimise.
GemCraft leans Optimization (Pure Optimization); Schedule I 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
Schedule I
First-person mixing and dealing chores, low dexterity
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
GemCraft
Monster waves are scripted, never adapting to player
Schedule I
Police and customers run mappable scripted routines
Schedule I leans a little harder on variance, though the gap is small.
GemCraft
Wave composition is fixed once a level is known
Schedule I
Customer demands and busts add light randomness
GemCraft leans a little harder on optimization, though the gap is small.
GemCraft
Combining gems for optimal tower output is the entire game
Schedule I
Product recipes, pricing and empire logistics are 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.