head to head
Portal asks more than Super Scribblenauts, and the gap is execution.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.

Optimization · Pure Optimization
Tests creative vocabulary - conjuring the right modified object for each fixed puzzle.
Portal leans Optimization (Pure Optimization); Super Scribblenauts leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Super Scribblenauts
Stylus control matters slightly, never decisively
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
No adversary modeling player.
Super Scribblenauts
Solo sandbox - nothing models you
Super Scribblenauts leans a little harder on variance, though the gap is small.
Portal
Deterministic chambers; no randomness.
Super Scribblenauts
Puzzles are fixed; your vocabulary is the only variable
Portal leans clearly harder on optimization.
Portal
Pure puzzle-solving optimization.
Super Scribblenauts
Finding object-adjective combos that satisfy each puzzle 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.