It's a game of two buttons (to paraphrase the football cliché) - iRunner has you sliding and jumping to duck under obstacles and jump over gaps. Good hand-eye coordination is needed, as is a deep wallet should you decide to enable the zapping of in-game ads and the saving of progress.... It's $50 (about £30!!) as far as I can see, having played it for a while. Possibly best avoided, especially if you might hand the game to a child, who will feel very free to spend away....

From iRunner's description in the Windows Phone Store:

iRunner is a fast paced running game, with great HD graphics and game control. Mr. i, as the hair shows, is running as fast as possible to mysterious destination.
You need to keep good tempo to avoid all obstacles on the way. Trying to collect as many batteries as possible while running. Collect gifts to turn into fever state - cooler dress, exciting tempo, and double score!

Intrusive game rules:
* Tap "Jump" button to jump.
* Double Tap "Jump" for sequential jump
* Tap "Slide" to avoid obstacles.

Highlighted features:
* HD graphics, fully large screen support including tablet.
* Very good an fast tempo, and awesome sound track.
* 16 glorious achivements to be unlocked.
* Three modes: Training, Normal, Challenge.

and many more features are waiting for you to explore in the game!

Here's iRunner in action:

The opening menu - ads on most screens in the game, by the way...

Goals for each level, plus the choice of which boosts to enable (depleting your gems count)...

Sliding and jumping across a side-scrolling landscape....

You'll need to buy gems to save progress...

... up to $51! WHAT!? I don't care how many virtual gems you get, the very fact that this is possible is outrageous. And worrying.

You can find iRunner in the Store here. Comments welcome - am I being too harsh? [hint: the answer's 'no']