Your finger is the dog! Just place your finger/dog near the sheep who are scattered throughout a level, and guide the back to the green pastures at the end of the level. Unfortunately these sheep aren't content with getting lost in a field, you're going to have to navigate a lot of tricky terrain to be a successful herder.

Pocket Sheep is a great idea for a game - for some reason I expect the sheep herding genre to be more popular than it actually is. At times Pocket Sheep feels more like a tech demo than an actual game, but with such a high concept game that's always going to happen.

The 'close' nature of the game also contributes to this. Admirably the majority of the levels are built around a single screen, which leads to some very small on-screen sheep, and not only your finger but your entire hand can occlude the screen. I found myself spinning my phone around to make sure I could see where the sheep were heading, while keeping my finger in touch with the screen.

Oh and you might need to use multi-tap to bring a second finger into play to scare the sheep.

Given the top down nature of the game, you might be surprised to find out that Pocket Sheep is powered by the Unity 3D engine. This isn't a surprise to Unity - the gut feel of the engineering department is about 40% of games that use Unity are built around 2D concepts - but expect more of this in the future as Unity bring 2D physics and scene editing to the gaming engine.

As a game Pocket Sheep is interesting and has a niche appeal (although if you're on one of the smaller screened Windows Phone handsets it's perhaps not best suited for that environment. I still think there's a lot of promise in a solid sheep game for Windows Phone. Pocket Sheep proves the concept, but it's still not the definitive title.

The trial version of Pocket Sheep is available through the AAWP App Store, with the full priced version costing £1.49 / $1.99.