The world of Oz isn't just about a yellow brick road, catchy songs, or lovable characters - as anyone who's seen the terrifying children's film Return to Oz will testify.

Oz: Broken Kingdom continues with that movie's darker take on Frank L Baum's magical world, but there's a bit more to the game than its moody - and often jaw dropping - aesthetics.

It's an RPG with a prominent collectible card game element in which you take control of Ophelia Shen (no Dorothy here) and her team of familiar faces - namely Tin Man, Lion, and Scarecrow.

You work your way across various maps taking part in turn-based battles, using offensive and defensive cards to unleash attacks and spells against a range of opponents.

In the later stages, it's important to take note of how they're set up and their specific weaknesses. You'll also need to customise your team to improve their power.

To help you make these decisions, tactical information is displayed before a battle that goes through a number of statistics to help you deduce your chances of success.

Then there's a HUD in battle that also displays useful information but, sadly, the information seems a little crammed in, so it can be a little overwhelming.

To combat this the game makes its levels short, with no more than three waves of enemies to beat in each - and with swift battle animations you can cut through multiple stages in no time.

There's also a slick online Arena mode where you can join a guild, employ further companions to your team, and battle other players in real-time to gain items and further strengthen your squad.

This is all wrapped up with some top notch presentation thanks to its crisp 3D visuals and detailed art. In fact, it looks so good that it was used at the Apple Conference earlier this month to demonstrate the power of the iPhone 7 processor, and it's not hard to see why.

So it's a little disappointing that with all these pieces in place Oz: Broken Kingdom is hobbled by its F2P mechanics - with several battles being near impossible to win unless you stump up for extra resources, grind away at previous stages, or wait for various item timers to tick down to zero.

This isn't a huge surprise considering the current F2P mobile climate, but unless you’re willing to splash the cash it does make it hard to fully immerse yourself in the world - forcing the tight fisted amongst us to experience the game almost exclusively through short (but sweet) sessions of play.