TowerMadness 2

Okay, so let's cut straight to the question that really matters here. What's so mad about TowerMadness 2?

Initial inspection reveals that it's both a tower defence game and a sequel. Hmm, that crazy gene must be be buried a little deeper.

Aha. The premise sees you defending a pen full of helpless sheep from alien abduction with a futuristic arsenal more suited to protecting a city.

Okay, Limbic Software, you win. That is ever so slightly nuts.

Hyper-vigilant animal husbandry aside, though, we should stress that this is tower defence by the numbers.

Stages vary between fixed-path trench runs, whereby you must position automated gun turrets along the enemy's predicted path, and freeform stages that allow you to lead the enemy a merry dance using the towers to erect makeshift mazes.

This approach is very Fieldrunners 2, as is the selection of towers. There's the one that fires area-effect mortars, the one that slows the enemy down, the one that burns through multiple units simultaneously, the one that zaps them. You get the drift.

The upgrade system, too, will be familiar to genre enthusiasts.

Of course, familiarity doesn't necessarily breed contempt in the world of video games. TowerMadness 2 might be unoriginal, but it's still good fun.

Its chunky graphics aren't immediately impressive, but when you start zooming in and out with dozens of attacking units on screen at the same time with nary a hint of stutter (even on our 'old' iPad 3) you'll realise the strength of the engine.

TowerMadness 2 has a couple of neat touches of its own, too, such as the environmental effects that the second and third worlds have on your towers (overheating and icing up respectively). Watching your last-ditch ram defence sending a whole line of aliens packing is also a treat.

The game also balances its cheeky humour well with stages that will seriously challenge your forward-planning abilities, mixing things up just enough to keep you moving on.

TowerMadness 2's biggest issue, aside from a general lack of originality, is its IAP system. This is a game that costs £1.99 to purchase, but is structured to strongly encourage further payments.

It's annoying, for example, that you have to purchase additional tower slots, or else commit to grinding for wool (the game's currency, which can of course be bought with YOUR currency).

For those who don't want to pay, it adversely affects your enjoyment of the game, as fewer towers means fewer options and less tactical scope.

Of course, you can unlock the ability to double the amount of wool you earn in each round, but at a cost of another £1.99.

The truth is that TowerMadness 2, despite its name, is a very straightforward tower defence game. Even the first game in the series, which was launched way back in 2009, felt very familiar at the time.

The perverse thing is that if this sequel had stuck with a similarly old fashioned payment model, it would have felt quite refreshing amidst all the irritatingly grabby IAP-fests we see today.

That TowerMadness 2 fails to do this doesn't mean that it's a bad game. It just means that it's tougher to recommend, and thus a little more forgettable than it should have been.