With so many mobile games these days apparently designed to save you even the merest hint of stress and exertion - bombarding you with points and prizes whatever level of success or failure you attain, because you really are a special little snowflake - it's nice to change things up once in a while with a game that is neither easy nor particularly rewarding. At least not in the frivolous sense 'rewarding' has come to mean.
Hoggy, by Raptisoft, doesn't shower you with stars, high scores and multipliers every time you paw your iPhone, it doesn't give you much acknowledgement that you're doing well, and it doesn't even tell you when you've cocked up a level irretrievably and need to start again, leaving you to figure it out. All the same it's quite wonderful.
It's a platform puzzler that looks a bit like various Super Mario Bros. games and involves collecting fruit in 2D multi-screen levels. You manoeuvre around by tilting left and right, but you can't jump or attack or anything - instead you jump between and stick to the floor and ceiling by tapping the screen. Collect all the fruit and you get a key; get a certain number of keys and you can unlock the next chamber of levels in the hub area you move around in between them.