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
Tests creative vocabulary - conjuring the right modified object for each fixed puzzle.

Optimization · Pure Optimization
Coordinating three characters through fixed object-logic puzzles.
Super Scribblenauts leans Optimization (Pure Optimization); The Cave 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.
Super Scribblenauts
Stylus control matters slightly, never decisively
The Cave
Undemanding platforming with no timing pressure
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Super Scribblenauts
Solo sandbox - nothing models you
The Cave
No adversary - a narrating cave is not a mind
The Cave leans a little harder on variance, though the gap is small.
Super Scribblenauts
Puzzles are fixed; your vocabulary is the only variable
The Cave
Each character's section is unknown on first descent
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Super Scribblenauts
Finding object-adjective combos that satisfy each puzzle is the game
The Cave
Three-character object-shuffling puzzles are the whole 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.