Welcome back to the In-App Purchase Inspector - our regular look at free-to-play games from the consumer's perspective.

In each instalment, we consider the incentives or pressure applied to make in-app purchases, their perceived value, the expansion offered by IAPs and the overall value of the experience.

The end goal is to see whether the game makes a good enough case for us to part with our cash, or whether players are content - or engaged enough - to 'freeload'.

This time, we’re diving into the depths of Hungry Shark World, the latest chomp-'em up in the series from Ubisoft-owned studio Future Games of London.

There’s always a bigger fish

The fifth game in Ubisoft/FGOL's Hungry Shark series, Hungry Shark World shares most of the core gameplay elements with its predecessors.

But there are some differences.

Its art design is more cartoony - potentially widening its appeal - while, more importantly, it's the first game in the series to be designed from the ground up with F2P retention and monetisation in mind.

You start off as a blacktip reef shark, only being able to munch on small fish, turtles, crabs and tourists. In total there are 17 different sharks to unlock.

In terms of gameplay - just as in nature - if it's larger than you, spiky or odd-looking, avoid it. Otherwise, eat it.

The more you eat, the more points you get and the longer you survive.

As you devour other creatures, you'll also be getting experience, and accumulating the game's two currencies: gold (softer) and gems (harder).

To bring additional spice to the experience, you'll come across gold fish to eat, which slowly fill up your gold meter.

When it's full, you enter the gold rush mode, which is a limited time period when everything is golden - a great opportunity to boost your treasure.

But, as with all endless games, at some point your shark's life will deplete and it will be game over, unless you spend some gems or watch a rewarded video ad (Mobile Strike most likely!) to regain your life.

There's a limit of two video revives, and the gem cost increases every time you die.

This is the key monetisation loop for Hungry Shark World.

Sunken treasure

Of course, if you want to progress faster in the meta-game, you can buy gold and gems in the store.

Prices range from 10,000 gold coins for $4.99 to 330,000 for $99.99.

For gems, it's 100 for $4.99 to 3,300 for $99.99. so you can see that each gem is worth 100 gold.

And gems are the really valuable option in terms of unlocking larger and more aggressive sharks.

If you want to grind to unlock them, you have to gain experience to unlock the next tier: the 17 sharks are arranged in 7 tiers ranging from small to XXL.

Splashing your cash with gems, however, means you could unlock the Great White Shark immediately - at least if you're happy to spend $60.

But if that's not your style, you can slowly level up your shark with collected gold, both in terms of speed, bite and boost performance but also with accessories that also provide small improvements.

The best are the pets - small R-Type-style power ups - which increase your points total as you play.

But you can also buy a pink wig, hula skirt, bow tie, sombrero, laser gun or tiki torch amongst many other items to pimp your shark, both visually and in terms of its characteristics.

Baiting the player

Still, it is easy to notice that, as you advance, the number of coins or gems needed to unlock sharks and buy goodies increases more rapidly than the number of gained coins.

This is where the main hook - no pun intended - of the game lies: the first few hours of Hungry Shark World boasts a smooth progression, but as you get to the more powerful sharks, IAPs become more and more compelling.

This is a great way to engage players, as by the time the game gets monetarily demanding, they're absorbed.

It sets a clear requirement: the way to access the best sharks is through commitment, be it in the form of buying hard currency or many hours of grinding.

What's the goal?

More speculatively, though, once players have unlocked the top tier of sharks, it's not clear why they would then stay playing.

There are daily missions but they aren't particularly engaging.

No doubt FGOL is working on content updates - new sharks, pets, environments - but more significant is the lack of competitive or multiplayer aspects.

Quite how a guild system or PVP mode would work in Hungry Shark World is another matter.

But, at present, basking in the success of 10 million downloads in six days, we can safely call Hungry Shark World a success for FGOL and Ubisoft.