For any long-running series, innovation is key to keeping fans coming back for more without getting too bored. Gameplay tweaks and changes to the setting can work wonders in refreshing a stale format, but some might argue that if an idea ain't broke, then don't keep trying to fix it. The Paper Mario series has been no stranger to these changes over the years, nor have recent titles avoided their fair share of controversy and scorn as they step further away from more traditional RPG roots. Things came to a boil with the release of Paper Mario: Sticker Star on 3DS in 2012, which some considered to be a drastic leap in the wrong direction.

Enter Paper Mario: Color Splash; it was revealed earlier this year to a lukewarm response and carrys with it the dubious honour of being one of the last major Nintendo titles on Wii U. In many ways it has something to prove, and despite following in the footsteps of that contentious Sticker Star format, it stands much taller as a more confident, complete title with a real sense of life and adventure to it. It hasn't revolutionized the system and isn't a total return to form, but we reckon there are enough welcome surprises in store to change more than a few uncertain minds.

The story takes place in an entirely new setting called Prism Island. It's a little bit Isle Delfino and a little bit Rogueport, but Mario and Princess Peach aren't lured there by the promise of a vacation. Rather, this island paradise is in total chaos as Bowser's paint-hungry troops run amok, draining the land of colour by slurping it up through straws. Teaming up with a lively paint bucket companion named Huey, Mario sets off to retrieve the scattered Big Paint Stars and restore order to this faded world, under threat of the mysterious Black Paint. Peach, meanwhile, is eventually kidnapped (gasp!) and reveals further twists in the tale through numerous Holo-Peach messages dropped across the island. She's clearly had a jump in technology from the days of frilly stationary.

It's an undoubtedly straightforward plot that's used as a mere launching point for what quickly becomes a fantastic, rollicking adventure. There's an added sense of 'oomph' to almost every single aspect of the game, despite sharing so many mechanical similarities with Sticker Star. Rough edges have been smoothed down, combat has been streamlined and, perhaps most importantly, the writing has received a major bump in quality. Moment-to-moment scenes and interactions brim with humour, charm and imagination, making it an absolute joy to discover new people and places as you progress. The world is once again broken up into a series of levels, navigated in a roughly linear fashion by moving around a map screen. While some may balk at the thought of that, there is however a real sense of place and progression as many levels are grouped into loosely structured 'chapters' of sorts, with plenty of areas encouraging revisits to make sure you've seen everything.

One of the biggest incentives to do this revolves around paint, and as gimmicks go this one ends up being a worthwhile addition, tying together exploration and combat in a few interesting ways. While venturing around the world, you'll come across many colourless patches which can be doused in paint by swinging your hammer. Doing this not only earns you some coins and other goodies, but can open up new pathways by repainting a doorway or colouring a moving platform to bring it back to life. In drastic cases you can even walk on entire oceans drained of colour, or safely navigate fields of lava by sticking to these empty blotches of white. Paint is therefore an important, limited resource which you can replenish by defeating enemies or simply by digging around the environment - smacking foliage will net you a few blobs of green paint for example, and breaking rocks will yield some earthy brown.

You'll want to keep your stocks high, as paint also plays into the game's revamped combat system. Following on from the basic formula used in Sticker Star, stickers have been replaced by a deck of item and attack cards. These range from basic hammer and jump attacks to some defensive items, healing, and more strategic abilities, but their real power is determined by how much paint you use to colour them in. Each one starts off blank, so when you play a card you'll essentially spend paint to make them stronger and have more of an effect. On your turn, you can actually play multiple cards at once, increasing the number from one, to two, to three as you progress. Turn orders and enemy types are an important factor to take into consideration because of this, as enemies react in a number of different ways depending on how you attack them. Experimentation is key to learning how best to tackle different encounters, with a simple example being the use of a POW block before trying any jump attacks on buzzy beetles, or finishing off your turn with a defensive card to minimise damage.

Managing your cards adds some strategy to battles, but the generally low difficulty level still leaves something to be desired. One genuine improvement is that you're given an actual reason to enter combat this time around, as defeating enemies will yield hammer medals that gradually fill a meter and level up your max paint capacity. This is a great idea in theory, as with more paint you can launch stronger attacks and don't have to worry as much about being so thrifty, but in practice you'll rarely run dry and can pretty much just power up every card without fail. While it's faster and more rewarding, combat is still far too basic to feel consistently enjoyable. We much prefer this system to the dreary routine of Sticker Star - you certainly don't feel punished for entering battles – but it's far from perfect. We suppose it's possible to artificially raise the difficulty level by limiting how much you allow yourself to paint the cards, but that's a bit of stretch. It's easy to buy pre-painted cards in the shop, and we never found ourselves too short on coins, cards or paint at any point. You can even spend ten coins in the middle of a battle to earn an extra card on your turn, which makes it much more difficult to actually run out of options.

That being said, there are some definite highlights to combat and we're slowly edging closer to a system that balances fun and strategy. Boss battles still rely on the use of Thing cards to complete them, but there are also sub bosses like Petey Piranha which are straightforward, enjoyable fights against challenging enemies. Even the main bosses, as frustrating as it is that you need a specific Thing card to beat them, have their own clever twists besides that. The Koopaling Larry, for example, sends waves of enemies at you as a brave Toad makes his way to the frontlines, and it's a genuinely difficult fight with multiple assailants to keep on top of. Unfortunately this is then trivialized in the second phase when it's revealed that you need a mandatory Thing card to continue, and if you don't have it in your deck then you've no choice but to restart the whole encounter. When it works, combat is fast and suitably frantic, but that's only half the time.

Thankfully, puzzles aren't nearly as repetitive, and while it may seem rather simple at first, Mario has actually got quite an array of abilities to keep in mind. When splashing paint around the environment doesn't work, you can always tear away certain pieces of the cardboard landscape by tugging on loose edges, or even snip parts of the world away entirely using the Cut Out technique to line up geometric shapes and use them as a hidden path. This is also how you place Thing cards into the environment, using giant 3D objects like electric fans to create gusts or wind, or unplug pipes using massive plungers. After all, we're pretty sure that's supposed to be Mario's job. Special Unfurl blocks also allow you to create shortcuts out of certain objects, and there are hidden paths everywhere just waiting to be spotted by keen eyes. In fact, there are even members of the rescue squad to, er, rescue; they have some pretty tricky hiding places indeed.

It's in the exploration and level design that the game truly surprises in all the right ways. Every area has at least one mini paint star to find, acting as a reward for clearing an objective, but many levels hold multiple stars; each one you collect opens up a different path to another area of the island. Some have little to no combat at all, and one moment you could be cooking up a Mamma Mia pizza while the next you're trying to outrun a train. Tapping up on the D-Pad will have Huey advise you whether or not there's anything else to be found in your current location, which alleviates having to run around mindlessly hoping you'll stumble across something new. On the contrary, you'll rapidly find new places to visit even while backtracking, as the world changes around you and certain quest-lines carry across a handful of different locations. Levels flow into each other nicely too, with archaeological dig sites giving way to the chief scientist's cosy home, creepy hotels leading into even more spooky grounds outside, and it isn't long until the whole island feels like one cohesive place, despite the fact it's divided up as points a map.

This is helped tremendously by some of the best presentation we've ever seen in a Wii U title. The range of colours, the quality of the texture work and the sheer imagination put into designing some of the areas you'll explore is incredible. Even rendered as paper-thin dioramas, they feel remarkably convincing and bring new life to even the most bog-standard forest setting. There are some exceptions to this - the RoShamBo Temples are all basically identical, though serve as little more than money farms - but even the lack of visual diversity amongst some of the NPCs is lessened if not nullified by the wide range of personalities on show. With the writing being as strong as it is throughout, even the plainest of Toads are far from stoic 'shrooms on Prism Island. We would have loved to have seen the environmental diversity carry over to character design as well, but whether it's a surly construction foreman or a nervous pirate captain, thanks to some excellent dialogue they each feel unique in their own right. Some moments had us genuinely laughing out loud, and at one point you'll even have a heart-to-heart with a Shy Guy, which is a lot more emotional than you might think...

That is to say nothing of the stellar musical soundtrack, which is filled to bursting with so many excellent tunes that we couldn't possibly begin to list them all. Jazzy, brass band pieces get things off to a flying start in earlier levels and also serves as the main battle music, but there are also haunting melodies, harmonica-laden country jams and rhythmic sambas to enjoy. In fact, every time you rescue a Big Paint Star, the entire town of Port Prisma unites in a dance routine, just one of hundreds of little quirks that are bound to keep a smile plastered firmly on your face. Best of all, submitting cards to the town museum and completely repainting different levels will unlock concept art and music tracks to check out whenever you like. All of this runs at a solid 30 frames per second, with only the occasional dip when things get particularly crowded.

The Wii U GamePad is your only option for controller support – with the ability to go off screen if you wish - but you can choose whether to use the touchscreen or physical buttons to select and play cards during battles. In a neat touch, while planning your attack enemies will also blurt out little quips on the TV screen as you decide on a move, and it's nice to see even the tiniest Goomba still shows a bit of bravado. There's only one save slot available for each player (though that shouldn't matter if everyone has their own profile on the console), but the main adventure will take well over 20 hours to complete if you go at a reasonable pace.

Conclusion

Paper Mario: Color Splash isn't just painting by the numbers. The series still straddles that awkward middle ground between pure RPG and adventure title, but this most recent entry has successfully found a comfortable niche that has silenced many of our prior gripes. Almost everything has been polished to a papery sheen - showcasing some of the series' best writing and presentation to date. Both the battle system and the overall plot are still some of the weaker aspects of the experience unfortunately, though they're moving slowly in the right direction.

Simply put, even when we were left unsatisfied by enemy encounters, Prism Island was always a joy to explore, with diverse environments and an endless amount of catchy tunes to keep you engaged from start to finish. It's a game of memorable moments that we would love to share but wouldn't dream of spoiling on you. Take Color Splash for what it is, and you might just find it to be a messy work of art.