If there's a lesson to be learned from Slime-San, it's that looks can be deceiving. Glancing at screenshots reveals a grungy, pixellated style, some weirdly gooey environments and what would appear to be a fairly straightforward 2D platformer, but scratch just beneath the slightly viscous surface and you'll find an unashamedly weird and wonderful title that's eager to smash any expectations you may have had. If you've been looking for a quickfire challenge to pick up and play on the Switch, then this might just be the slime for you. Oh - and if there's a second lesson to be learned it's that you should never ever trust a giant worm. They're evil.

Slime-san didn't follow lesson 2, and promptly gets eaten alive by the aforementioned giant worm as soon as the game begins. Now he and his bird companion must jump, swim, climb, and dash their way to freedom, with the beast's innards acting as the setting for 100 stages of manic platforming as you work your way from one end to the other. Each stage is broken up into four smaller levels, which - for the most part - take place within the confines of a single screen. They're all designed with intricate detail as a result, and although there's an implied route through each one, it's quite possible to break off the beaten path and find shortcuts, as long as you know what you're doing.

Thankfully, Slime-san himself controls beautifully, which is vitally important in a game that demands quick reactions and perfect timing. Using either the Joy-Con or the Pro Controller there's a real sense of control over a surprisingly versatile move-set, as the little goop can dash in mid-air, cling to walls, slow down time, and perhaps most importantly turn transparent in order to pass through certain blocks. The limited colour palette Slime-San uses is an important gameplay mechanic as well as a stylistic choice, tightening your focus around three key colours that carry throughout the entire game. White designates neutral surfaces, which will form the basis of your path through each level. Red is used to designate enemies, hazards, and anything else that will instantly kill you upon contact. Green blocks mean that you can pass through them by toggling your transparency, and this becomes especially important in later levels. 

All of that is definitely not to say that the game lives and dies by those three colours. In fact there's a really compelling gameplay cycle that constantly introduces new and varied mechanics, obstacles and enemies at a breakneck pace. We don't want to mention too many of these mechanics as it would spoil a lot of the fun, but suffice it to say that we were being surprised by new and inventive ideas all the way to the end credits. These mechanics are generally presented in isolation at first, giving the player time to understand them before slowly expanding upon that concept in subsequent levels. Toggling your ability to turn transparent will later cause blocks to appear and disappear, for example, and after a few levels you'll be using this skill to control platforms, guiding an enemy towards an important switch.

There's almost an element of puzzle-solving to later stages, as you take a moment to identify all of the hazards and analyse the best way to progress safely. Your goal at the end of each level is to make it to the checkpoint sign, though this is often easier said than done. Poor Slime-san doesn't even have the luxury of time, as a meter constantly threatens the arrival of deadly stomach-acid, which washes over the stage killing everything it touches. By the time you're a few hours deep into the game you'll have been battered and bruised for sure, with just one hit spelling death. But with such a quick reset you're encouraged to jump right back in and correct your mistake, combining skills to dance around multiple projectiles, dive through openings, and dodge enemies like a slimy pro. It's incredibly satisfying. 

Depending on your slime/skill level we reckon there's anywhere from about 10 - 15 hours worth of content to be had from the main story mode alone, but that isn't even close to all that Slime-San has to offer. There's an entire city buried deep within the giant worm, and touring Slumptown introduces a variety of lively NPCs to interact with, areas to explore, and vendors to deal with. You earn spending money by collecting the bonus apple within each level, which is a challenge in and of itself. These are often tucked away within hazardous dead-ends, costing you precious time and demanding no small measure of skill to retrieve, but doing so instantly rewards the player for tackling an additional bit of platforming. Choosing whether or not to seek out these collectables is a clever way to adjust the difficulty of each level on the fly, and once you've gathered enough there's a whole marketplace to peruse.

In Slumptown you can buy new accessories for both your slime and his bird buddy, spruce up the screen's borders with extra art, and even change Slime-san's abilities and appearance by purchasing entirely new characters. These represent pretty substantial gameplay tweaks, allowing you to trade in speed for a higher jump, or force the little guy to dash continuously. Finding the secret exit within certain levels brings in even more NPCs to the town, and earns coins that can be used in the arcade to unlock additional mini games. This dingy place - run by a vampire bat no less - features three separate titles that can be played either solo or with a friend. There's a Legend of Zelda-style gauntlet, a top-down shooter, and a version of PONG that's way more fun than it has any right to be, all with various difficulty modes and high scores to beat. 

This only serves to open the floodgates on just how much additional content there is to find outside of the main story. There's a boss rush mode, as well as speed-running options built into the game itself, which are extremely hardcore but allow for a customised challenge. Adjustments range from a single life run, to a remixed New Game+ that adds extra obstacles and rearranges enemy placements from the get go. There's also a test room where you can try out different manoeuvres without the pressure of a time limit, an option to simply jump into a totally random level, and you can even visit your heroic slime's family home, where you can get to know the locals and have a good nosey around the place.The settings menu alone is bursting with features, even accommodating for colour blind gamers with a variety of palette swaps to suit Deuteranopia, Tritanopia and Protanopia.

The fuzzy, distinctive visuals are reminiscent of the Game Boy Colour, with a '90s feel that manages to straddle the line between comforting and eerie. The NPCs are creepy but cute, the environments burst at the seams with minute detail, and the soundtrack is utterly fantastic, boasting a varied line-up of chiptune artists that match the aesthetic perfectly. It's like some oddball B-movie that you rented from a sketchy video store, and from the static of the pause screen to the incredibly convincing visual filters you can purchase - including one of the most realistic VHS effects we've seen in a long time - the whole game seems to embrace this vibe wholeheartedly. It delivers a unique blend of punk nostalgia with an urban Japanese style, and let's not forget this is all set within the guts of a giant worm, so it's an impressive feat to keep things so visually engaging. 

While performance is generally solid, during our playthrough we encountered a handful of situations where the framerate completely tanked into single digits for several seconds at a time, which caused a couple of pretty frustrating deaths. It's also possible to actually leave the confines of the stage in a few instances, which definitely wasn't intentional, but it's worth stressing that these isolated incidents were few and far between, with the majority of our experience running smoothly whether in docked or portable mode. It's also worth noting that some pretty exciting free DLC is also on the way soon, which will add even more hours of gameplay to an already substantial experience.

Overall, it feels as though Slime-San was a real labour of love from the development team. There's personality around every corner and a real attention to detail throughout, even reaching so far as the loading screens. While it was quite rude of Fabraz to steal all the best slime jokes for their own use (leaving this sorry writer with slim pickings...), it's fun to see the team poke fun at themselves by including lines such as "Ben insert pun here" or "Britt used mashed banana to make these noises" - just in case you were wondering how that nimble squelching was achieved.

Conclusion

Slime-san is a brilliantly snappy, charismatic and challenging title that manages to deliver a satisfying core game with tonnes of bonus extras to play around with besides. The controls are spot-on, the environments are varied and engaging, and while other platformers may have tread similar ground before, Slime-san weaves together so many different elements into a finely-crafted experience that it deserves a place among the best in the genre. That's not even mentioning a handful of arcade game modes, a suite of options for speedrunning, and a soundtrack that almost warrants the price of admission alone. It represents immense value for money, and if you're itching for something weird then the future is most certainly green.