No depth? Most games played on smartphones are designed for playing in short increments, many of them for playing with a single hand. That's what Super Mario Run is. It's designed so you can play in just a couple of minutes, and you can play with one hand while commuting, or like I did today, play with one hand while eating lunch.

As for clearing it in an hour, clearing each of the levels once isn't a challenge, nor is it the point of the game. If you want to complete the whole thing you must play each of the levels 4 times, and that's assuming you play perfectly each time (and you won't). And that's just for Tour mode. For Toad Rally mode you're competing against other people (not live, but against their time trial ghosts) and doing tricks to try and impress toads, where winning gives you a bunch of coins and a bunch of toads. And then you use those toads in the kingdom builder mode to unlock new items to put in your kingdom and to upgrade your castle, etc.

So yeah, you can play through all of the levels once pretty quickly if you want. But that's not really experiencing the game.