Devil's Third has had a protracted and curious road to the Wii U, with notable gaps between regional releases and the peculiarity of an upcoming free-to-play online version for PC. With its arrival in Japan and Europe we get to see whether it's seductive and alluring or, alternatively, a devilish disappointment. With much self-imposed hype and a long development cycle, we're left with an experience as mixed as it is perplexing.

The first game from Tomonobu Itagaki's Valhalla Game Studios, this has been years in the making - originally planned for Xbox 360 and PS3, the folding of its original publisher (THQ) saw an unlikely alliance formed with Nintendo to bring it to Wii U. In the small but accomplished Wii U retail library it holds a unique place - it's mature in every sense of the word with gore, swearing and plenty of abs and curvy behinds, and it's a shooter / melee hybrid. There have been occasional mature games on the system - such as the outstanding Bayonetta 2 - and Devil's Third joins the ranks; as a result it carries the expectation of those hoping for an experience to broaden the Wii U's appeal.

Conceptually, Devil's Third has a lot going for it. It has a bold ambition of combining FPS action with intense melee combat, encouraging strategies that utilise both styles liberally. In the proof-of-concept documents and videos there's no doubt an emphasis on taking out enemies from range before charging in, sliding along the ground and then landing a stylish jumping attack. When this is pulled off it's fun, too. There's also the promise of two significant portions to the game, with the '80s action movie-style campaign and a heavily customisable and involving online component.

Let's tackle each individually and get the weakest aspect out of the way - the single player campaign. We've mentioned its stylistic approach to story-telling already, though its yarn of a post-Satellite technology world and terrorists attempting to blow everything up is mildly entertaining in its way. It's all cliché and rather generic - including 'infected' villains with special abilities - and is eye-rolling at times, but it has a charm to it nevertheless. We could easily pick apart its ludicrous plot holes and the sheer silliness of it all, but that'd be like sending a Broadway theatre critic to review The Expendables; we can accept that it's dumb.

The madness of it does lead to some memorable moments, particularly in the last hour or two of the campaign; in fact, it feels rather like the development team sunk most of its efforts in the extended finale, such is the scope and drama that's mustered. With nine core missions (which can take about an hour each to clear) it's the last two or three that show the bombastic approach at its best, with the finale actually being rather good.

Those are the positives, but unfortunately they are outweighed by problems. Primarily they're of a technical nature, in the process highlighting the protracted development cycle and poor optimisation - in this case - of the Unreal Engine on the Wii U. The game may have a soundtrack that's downright entertaining at times, but this is a poor showcase for the Wii U visually. Not only are the visuals out-of-date and ugly at points, but they reflect a lack of innovation from Valhalla Game Studios; an alternative style could have delivered enticing looks and solid performance, as has been achieved in many eye-catching Wii U games.

Instead, we have a relatively ugly game and unforgivably poor performance, and it's this frustrating framerate that is the most important flaw. Not only does it regularly dip, but there's persistent and off-putting judder on a frequent basis, presumably while the game is attempting to load assets in the background. It is, as a result, an unpleasant first-person shooter, with dodgy performance exacerbated by a poorly executed aiming reticule. Aiming is stiff and it's therefore difficult to find precision, with a deadzone on the analogue stick (whether on the GamePad or Pro Controller) that is strangely prominent. Having experimented with settings we were left with the choice of enabling aim-assist, an option this writer generally prefers to turn off in shooters.

Beyond poor performance Devil's Third is also a buggy game - sometimes humorously so, often enough to frustrate. Animations glitch out, AI shows a complete lack of intelligence, and a neat melee finisher move may clip through a wall in the wrong situation. It's a scruffy, uneven experience.

Technical issues are combined with bizarre design missteps. There are occasional flashes of brilliance, particularly in the latter levels, which raised a smile and boosted our overall impression of the game. But the lows are painful and all too frequent, which in some respects recreate Itagaki-san's trademark approach but in all the wrong ways. This is a shooter where small areas are frequently overloaded with enemies that in some cases gleefully fire rocket propelled grenades into your face, or throws in multiple heavily-armoured chain-gun wielding enemies that take far too much damage. Throw in glitches that'll cause crucial weapons to disappear (try destroying a tank with constant grenade reloads because your RPG glitched out) and there are moments of utmost frustration. A vehicular section is particularly bad, and some shooting gallery sequences are also shoddy; amateurish moments like these drag the whole experience down.

Overall, then, the solo campaign is a mixture of fun and frustration, ending with it being rather forgettable. It can be revisited in Score Attack, in which you tackle stages at a high difficulty to accumulate scores that are uploaded to leaderboards. The problem with that is that the range of issues make playing on a high difficulty setting an endurance reserved for the most committed. Overall, it's disappointing in the context of the genre-changing and thrilling experience that was promised.

Based on the single player campaign Devil's Third would not get a recommendation from us, especially as it's launching at full retail price, but the online component is a game changer. It's not enough to make Devil's Third a must-have, but it saves this release from being entirely skippable.

After customising a character with relatively basic options, you dive straight into buying early gear to prepare for battle. We initially received a chunk of 'Dollen' money and a batch of 'Golden Eggs' - more on those later - with greater rewards once the solo campaign is cleared. There are a whole load of initial weapons to choose from, which sets up the potential for loadouts of varied melee weapons and shifting between assault and sniper options, as examples. Trading some Golden Eggs for cash allowed us to setup a decent loadout.

There's some backstory around trying to survive and prosper in a post-Satellite North America, boosted with some neat in-game memos, but the setup is relatively simple. Ten varied and chaotic arena modes are eventually available with some unlocks - they vary from standard fare such as Battle Royale and Team Deathmatch, to modes such as Chickens in which you have the barmy task of catching the birds. Close Quarters and Gladiator are all about melee combat, while Carnival necessitates carrying watermelons to grinders. Most players seem to gravitate to standard modes, but there are some peculiar and fun alternatives on offer.

The arenas themselves, meanwhile, are somewhat hit and miss. There are examples that encourage you to alternate between loadouts, which is decent design - sometimes being a sniper is the right solution, while in other areas close-combat is a must. Most of the arenas are solid, though there are a couple of duds; one takes place at night and has barely visible falls into water, prompting farcical scenes of suicide notifications every 20 seconds. Overall, though, there's a decent range of environments.

Once you level up (to level 5), meanwhile, you unlock the real meat of the online aspect with Siege mode. It's here that you establish a base and either create or join an online clan which can have a lot of members. Structurally you establish your base in a specific territory, and when that's combined with the bases around the country from others in your clan you have a combined influence and power in each respective region. You can be a mercenary for hire in clan battles, but the best experience is within a group.

When part of a clan there's an impressive sense of camaraderie. Clans have their own Dollen stashes and regular payments are made to members to help their individual progression. You not only customise and develop your own fortress (such as adding turret guns, buildings etc), but you can pitch in and fund useful items for your overall clan, such as powerful air-based weapons. As a group you can then raid other clan's fortresses, defend your own when invaded and even establish diplomacy and non-aggression pacts with other groups. The diplomatic aspects are for the clan's founder, so if you want to enjoy those features you should create your own.

There's impressive depth here, and unlike in the solo campaign - where it does nothing but Off-TV mirroring - the GamePad screen comes into play. It provides a handy interface with a Mailbox and plenty of information, and text chat becomes crucial; we would dip into our clan's message room and plan an attack, rejoining after a battle to talk over how it went down. There's no voice chat, unfortunately, which would have been a welcome inclusion.

The attack and defence mechanic works nicely. It's best to check other clan members are up for a challenge before launching an attack, but notifications pop up to let you know if your clan is launching an attack or on the defensive; you then rush to the area to lend a hand. Victories boost your clan's bank balance (and your own) while also boosting its overall level and influence in the battleground's territory.

We played this mode pre-review, with limited numbers, and then over the launch weekend in the real game. Perhaps reflective of poor sales there were modest numbers online, but we did manage to get into some fun Seige battles and defences with almost-full lobbies. An issue is that in the early running two clans are far more powerful than many other start-ups, making it a two-horse battle. That aside, going into multi-phase assaults on enemy bases is undeniably fun, especially when there are strong players utilising some clever aerial bombardment tactics. It's chaotic but enjoyable.

It's a substantial online offering, all told, with solid variety. Siege battles that we've seen are fascinating for the clan dynamic but fairly straightforward in execution - defend your base, blow up the oppositions'. Drills provide the mayhem that Itagaki-san seems to crave, and it all operates pretty smoothly. We've experienced some relatively lengthy load screens, not uncommon in online multiplayer games, but we've noticed improvements too. Though the framerate is still not as high as it should be it is nevertheless more reliably smooth than in the single player campaign; this is aided by simple visuals, admittedly, but the gameplay is more important here.

To be clear, it's still not as technically accomplished as it should be and aiming is still not as smooth as is typically required, but these shortcomings are relieved a little by the silly modes, hefty clan dynamic and the fun of the melee/FPS hybrid gameplay when fighting other human players. It's an interesting experience in that sense, and is rather like the fast food of online shooters - it's not of the highest quality, but it can be satisfying.

Of course, we should mention the Golden Eggs. These drive microtransactions which, in the view of plenty, shouldn't exist in a full-price retail game. You receive a decent batch when you first register and when achievements are cleared; there are certainly enough to convert into plenty of Dollen and pick up some equipment. That said, it's naturally weighted to try and tempt you to buy, and it's slightly sleazy in execution. Plenty of stat-boosting equipment can only be bought with Golden Eggs, while the better options of the hugely powerful X-Gear weapons (which become available in-game when you string together plenty of kills) need a lot of these eggs to buy. It'll be possible to get by without buying them, but they do provide a clear advantage.

Overall, then, Devil's Third comes with two sides. A sloppy and messy solo campaign with only occasional flashes of quality, and a scruffy online component that - despite B-list production levels - offers plenty of depth on a level not found anywhere else on the Wii U. The gameplay still isn't perfect online, but it's had a lot of care and attention put into its structure with seemingly endless scope.

Conclusion

Devil's Third is an odd beast, seductive and alluring in some respects and nightmarish in others. The solo campaign ultimately isn't good enough; occasional positives are eventually overwhelmed by bugs, poor design and technical issues. The online multiplayer, while still a little lacking mechanically, is a more fun gameplay experience; it's also surprisingly deep in structure, and one of few online feature-sets of its type on Wii U. Plenty of 'Drill' modes and the impressive fortress / clan setup in Siege mode are notable, with the only major downside of the online component being unnecessary microtransactions.

Devil's Third is tricky to recommend, ultimately. There's undoubted fun to be had online, but at the same time this is an action game that sells Wii U gamers short. It's packed with good intentions and ambition, but Valhalla Game Studios was unable to execute its vision well enough. The devil is in the detail, and that's the problem.