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 · Systems & Chaos
A grindy collect-them-all brawler driven by random toy drops.

Optimization · Practiced Mastery
Routing efficient digs and upgrades through a randomised mine.
Pokémon Rumble Blast leans Optimization (Systems & Chaos); SteamWorld Dig leans Optimization (Practiced Mastery).
SteamWorld Dig leans a little harder on execution, though the gap is small.
Pokémon Rumble Blast
Two-button mashing with minimal dodge demands
SteamWorld Dig
Digging and platforming need modest precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Pokémon Rumble Blast
Toy Pokémon swarm on simple scripts
SteamWorld Dig
Enemies follow simple fixed patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Pokémon Rumble Blast
Random toy drops and stats drive collection luck
SteamWorld Dig
Randomised mine layouts hide ore and hazards each run
SteamWorld Dig leans a little harder on optimization, though the gap is small.
Pokémon Rumble Blast
Grinding stronger toys and move choices carries progress
SteamWorld Dig
Upgrade routing and efficient dig paths drive progress
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.