Yes! It's based on a few arbitrary factors such as the amount of steps you take, how many monsters you beat, etc. There's nothing tied to the score; just another way to give people different experiences during their play!
What's the best score?
The best Grade you can get is an "S" with 3,000 or more points.
The highest theoretical score you can get is 3,700. I never actually gotten it myself, only up to 2,900 personally.
Damn, I got 2,700 on my run. How i'm supposed to get another thousand is a mystery
