Believe me, Nintendo's making their money on the back-end with this one. They're intentionally pricing it low, in order to attract 50 million people, instead of 5 or 10. The value of the game, because of the platform it's on, should not be interpreted either way simply because of the sale price. I'm sure it's a reasonably full-length game. Nintendo doesn't skimp on quality or content.
I'd wager that simply by increasing the price form 9.99 to 10.99, they'd be chipping 20% of the potential audience away from buying the game.
Mobile is a different beast than console. Mobile players are conditioned that everything is free, or "nearly" free. I'm actually a little surprised Nintendo's not going 5.99 or 6.99 on Mario Run. The fact that they're pricing it at 9.99 is actually pretty bold of them. If 9.99 works as a mass market price on iOS, then Nintendo will use this to determine what to price Animal Crossing and future game-centric apps in 2017 and beyond.
The Screamapillar is easily identified by its constant screaming—it even screams in its sleep. The Screamapillar is the favorite food of everything, is sexually attracted to fire, and needs constant reassurance or it will die.
