Double Fine's Hallowe'en-themed RPG makes an unexpected - if timely - return on iOS, with this fine port. It's a welcome opportunity to revisit a simple but enormously likeable game that captures the glee of a night spent trick-or-treating.

Of course, such a mundane activity needs a little extra narrative spice, and it comes when sniping siblings Wren and Reynold are suddenly separated, with one of the two (you have a choice of either as your playable character) kidnapped by goblins.

Your job, then, is to rescue them - though you'll still need to ensure your bag of sugary treats is regularly topped up along the way.

Candy rush

In the simplest terms, Costume Quest plays out like a JRPG for kids. You encounter an enemy - either behind the door of one of your neighbourhood's houses, or, later, walking around the streets - and fight it in turn-based combat.

As with the Mario & Luigi games and many others of their ilk, you can boost your attack power by performing an additional action, like tapping a coloured icon or swiping the screen rapidly.

Likewise, you can minimise the damage from enemy attacks by pressing the right button before the blow connects.

It's simple stuff, and it doesn't vary much from beginning to end, but the battles are briskly paced, and the costumes you and your trick-or-treat partners wear add a very light tactical element.

Urban outfits

Yet if the game is fairly rudimentary in mechanical terms, it more than compensates with warmth and charm.

The writing is excellent, with brilliant lines for the vast majority of NPCs - particularly in the early stages, where you encounter kids wandering around in a variety of costumes, from Abraham Lincoln wannabes to bananas.

Meanwhile, you and your small party get to choose from a range of outfits - once you've collected the individual parts, at least. A sheet, some cardboard, and a feather duster become a Statue of Liberty costume, and there are many more to find.

These are used to solve basic puzzles - a knight's shield allows you to pass by a water pipe without getting your cardboard costume wet, for example - but they also have different movesets and special abilities in combat.

Robots in disguise

As half the fun is discovering what they do, I'm not about to spoil them here, but suffice it to say it's worth locating them all.

There's something oddly touching about the transformations they provoke, too, as a small kid in a home-made cardboard outfit suddenly becomes a giant, missile-firing robot. It's like you're witnessing the moment when a child's imagination takes flight.

The side-quests, while rudimentary, only add to the appeal. You can customise your costume with stickers for various buffs, or collect trading cards that can be swapped with other kids.

They're bursting with excitement when you give them the card they've been seeking for so long, and the dialogue that accompanies the exchange rings wonderfully true.

Short but sweet

Costume Quest doesn't outstay its welcome, either - you'll be done in around five hours, which feels about right given the limited nature of the combat.

And if you haven't had enough, for a small fee you can then play through the equally engaging Grubbins On Ice episode, a festive treat that adds a few new costumes.

In fact, my only real complaints are with the port's technical shortcomings: the battles take place in a small window, while the frame rate can chug a little while you're exploring.

Still, these are minor disappointments rather than serious flaws. Costume Quest is a witty, warm, and altogether wonderful adventure that will leave you on a sugary high.