"Rules are made to be broken," goes the saying. It's a load of rubbish, of course.

Not only do most rules maintain a vital sense of order and safety in our day-to-day lives, but they also form the basis of every game you've ever played. No rules, no fun.

Rules! gets all meta on us by being a game all about rules - and I for one am more than happy to be held to them.

Running the rule

Rule 1: "Tap numbers in descending order"

That's how each round of Rules! starts. This first level presents you with a 4x4 grid of numbered cards, each featuring a colourful animal, monster, or object on it.

So, touch the numbered cards in descending sequence, before the 20 second timer runs down. Easy!

Rule 2: "Tap greens"

That's the same every time too. Now you need to tap all the green cards. But what's this? You then have to follow rule one immediately after, all within the same time limit (which can be extended through strong performance).

And so it goes, Rules! adding consistent rule upon rule, the timer ticking as you struggle to remember what once was simple.

By the book

Rules! already feels pretty fresh at this point, as you inch your way towards Rule 10. Besides the original premise, it's got a nice art style, with off-white backgrounds and stylish fonts and cute characters.

Still, I could see the concept wearing slightly thin as I broke through rule 10 - only to find that the developer wisely resets the rule counter at this point, supplying a fresh batch of puzzley parameters to keep your brain ticking over.

This second batch adds new creatures (birds), and introduces such tricky delights as tapping adjacent monsters, testing your observation as well as your memory skills.

I haven't managed to get that far yet, but I'm sure there's another reset and more surprises from level 21 onwards. After all, Rules! is a game all about, well, rules.

It's at its most charming and compelling, though, when it subtly tweaks and expands on those rules, whipping the rug from under you and your gently frazzled memory.