There's an old marketing adage that 'less is more'. It's a tired cliché, and parroting it in an occupied room as if it were a genuine observation is entirely likely to give rise to a loud "urgh" from no-one in particular, but there is a seed of truth to it. It's a seed that's buried deep in Kingdom Hearts 3D: Dream Drop Distance, a game packed to the brim with features and mechanics and minigames and functionalities. It's full to burst, but the worst part is that it's really hard to work out why.

In part, this is why this review comes a month after the game has dropped. Kingdom Hearts 3D is packed with material, and if you base your assessment of a game's quality on how much of a time-sink it is, you're going to be over the moon.

Players start any given world (of which there are seven, some of which are repeated) with a Dive, a freefall mode resembling the flying parts of Kid Icarus: Uprising that manifests itself as an obstacle course or a boss battle.

Once in that world, there are several combat systems to master - the simple hack-and-slash of the Keyblade; the ever-specialised, ever-expanding Deck Commands; the weaponised parkour of Flowmotion; and the touchscreen-based combat-minigame hybrid that is Reality Shift.

There's also a new party system, the Pokemon-esque Spirits, predicated on the collection of Dream Pieces, and that opens up new possibilities for combat in the Link System and the Ability Link Board. It also opens up new obligations, in that players have to dedicate time to 'nurturing' a character’s Spirit by patting it through the touch-screen and playing object-based mini-games with them.
Players must navigate several areas within this world, battling waves of Dream Eaters and accessing special Streetpass-activated Friendship and Battle Portals, before fighting a boss whose patterns often reveal no obvious weakness and who often represent aberrant spikes towards insanity in the game's difficulty curve. Once a world is completed, characters can then move to other worlds or play 'Flick Rush', a mini-game that pits Spirits against other Spirits through the medium of card battling. Oh, and both characters, Sora and Riku, must complete each world.

For a handheld game, that's an impressive, even audacious amount of content. That Disney and Square Enix managed to fit all of that onto one card is worthy of praise, albeit a sick, twisted kind of praise. This is, after all, unfettered indulgence. But step back from being dazzled by the sheer volume of material the game provides, and Kingdom Hearts 3D starts to look less grand and more bloated, the result of a development studio that didn't know when to stop.

Modes like Flick Rush add nothing to the game outside of a mindless diversion; Reality Shift adds an unnecessarily clunky extra functionality to a combat system that's already complicated and unwieldy enough; the nurturing of Spirits seems to be a thing only because some developer at Square Enix played Nintendogs once and kind of liked it; the boss battles are such a trial that it's hard to see why the game needed so many of them.

It's especially irritating because, underneath all of the garish bells and shrill whistles, Kingdom Hearts 3D is a highly enjoyable, accomplished game. Kingdom Hearts has always managed to trigger good vibes as a result of its clever, synergy-centric melding of JRPG sensibilities to the cuddly Disney canon, and that's no different here, with excursions to Hunchback's Paris, The Three Musketeers' France, and Tron: Legacy's The Grid, among other locations. The attractive yet functional evocation of these locations – combined with the blatant trading on Disney's goodwill – makes the game worlds fun to explore and the combat vibrant and unpredictable enough to keep it fresh.

Further, with the introduction of Flowmotion, Kingdom Hearts now offers an incredibly streamlined and surprisingly versatile way of tweaking combat to the player's advantage, affording him or her with greater flexibility in high-pressure battles and more powerful attacks by way of a simple control scheme. Carving through hordes of stylishly-designed Dream Eaters is satisfying as a result of Flowmotion's accessible battle advantages.

But it's hard to be on side with a game that doesn't know when to stop. The gameplay is bogged down in unnecessary complications and not-so-helpful mechanics. On top of that, the narrative is representative of some of the worst excesses of JRPG writing and simplistic Disney morality. It's a storyline mired in an excess of characters, timelines and dense background information (the Reports menu, which carries explanations and backstories for the game's many facets, has no less than seven submenus, at least three of which pertain to the main narrative itself), and it's very easy to become lost in the narrative strands intersecting in all sorts of incomprehensible ways, especially for those unacquainted with all of the games in the Kingdom Hearts series.

The dialogue is also heavy with inane speech-making about friendship and the predictably simplistic difference between right and wrong – dialogue that becomes all the more treacly when pouring from the mouth of someone as saccharine as Mickey Mouse.

Kingdom Hearts 3D has a really good game, perhaps even a great game, at its core. The slick central combat mechanics, sharp graphics, colourful neon-laced design, and childhood-baiting Disney properties all combine to present a game that is often a lot of charming, exciting fun. However, the adage still stands - less is more, and these positive attributes could be so much easier to enjoy if they weren't being broken up by bad writing, frustrating boss battles and a ludicrous excess of development.