Mobile is a great place to find all kinds of simple and charming games, and one you need to play now is absolutely Archero.
In Archero, you play as an archer who is tasked with delving into dungeons and destroying hordes on monsters. You know, the usual business.
This game is incredibly simple to learn, but tough to master, and is incredibly rewarding. It's worth your time to download and play, but before that, read through these tips so you know everything you need in order to progress fast and beat down enemies.
Stop, shoot, move
The mechanics of Archero are simple, and yet that's why the game is so very addictive and satisfying.
All you need is a single thumb to operate the digital analogue stick, and you're golden. You either move, or you let go and stand still. That is the grand total of your interaction with the game, and it works magnificently.
You move solely to dodge projectiles, and better position yourself for attacks. That's it. When you let go, you start attacking instantly, as fast as possible. As first it seems simple, but the difficulty quickly racks up.
This is a roguelike, so each time you attempt your run things will go differently. A variety of power ups will be introduced, giving you the ability to shoot more projectiles, have more health, and other cool effects.
You can of course become more skilled at the relatively simple mechanics, but more than anything your progression is kind of dictated by which power ups you'll receive. You just have to get lucky, basically.
So it can be a game of try, try, and try again, but when everything comes together it's just wonderful.