A walk in the wood is usually quite peaceful, but one giant snake can ruin the whole thing. Slime-san was out for a walk, or possibly just squidging along in a slime-y way, hanging out with his bird-friend and taking in a bit of nature, when a particularly large and hungry bit of nature decided to take in him instead. In a surprising revelation, though, it turns out snakes have a rich internal life. Maybe metaphorically they’ve got a great imagination, but in this case it’s far more literal. The city of Slumptown is in there, as are hundreds of platforming levels plus a huge amount of hidden secrets and bonuses. Escaping the snake’s digestive system is a major task and by no means a simple one, but Slime-san has most of the jumping skills to manage the many hazards and challenges along the way.
Slime-san is a single-screen high-challenge platformer where each each level consists of four unique stages, one screen after another, constantly changing the level tools and mechanics along the way. The slime has only two extra abilities outside of its standard jump, and the in-level toys take care of the rest. The dash move is fairly straightforward- zip along in the direction you’re pointing, whether in the air or on the ground to cover distance quickly. It’s great for getting extra air time, and when coupled with the wall-jump it allows Slime-san to go pretty much anywhere. Slime-san can’t actually stick to walls, and instead slides down slowly, but once he’s touched a wall he’s got a spare jump to use either while clinging or after falling off. When coupled with the dash this allows advanced mechanics such as falling off one side of a wall, doing a mid-air jump underneath the overhang, then dashing straight up to cling on to the other side, all without ever touching the ground. Slime-san is the kind of platformer that isn’t shy about creating levels to exploit its physics tricks, demanding nimble fingers and perfect timing from the player.
Slime-san’s other ability is a phase move, which initially allows him to pass through anything green. The entire game is made up of five colors- red, white, green, and two shades of blue, and each one means something. The blues are for background, white defines the level surfaces, red is doom to anything that touches it, and green is useful. A green block can be used as a platform, but hitting phase lets Slime-san pass on through like there’s nothing there. Phasing also slows down the level, almost but not quite being the slime version of bullet time. The level timer is still ticking away at standard speed but everything is moving more slowly. What this means in terms of level design is that it’s fair to put a green block between two red ones, arranged vertically, because a jump-phase-dash move to get through is much easier when you’ve got that little bit of extra time to line up the shot precisely.
While Slime-san’s moves are relatively simple, that just leaves plenty of room to play with level mechanics. The dash move is used to push or break blocks, other blocks appear or disappear when phase is in use, entire rooms are built around the interaction of red and green walls, and it wouldn’t be much of a platformer if conveyor belts and icy floors didn’t make an appearance. Slime-san rarely sits still for long, introducing new wrinkles and mechanics only a level or so after the last. Thin passages with trampolines top and bottom so you need to dash away to avoid bouncing endlessly, red crawly things that find a slime tasty, doors that teleport you from one part of the screen to another, and of course the rare secret exits all make a platforming slime’s life just a little trickier.
While Slime-san is by no means short on platforming content, there’s also a huge amount of extras kicking around in Slumptown. When you’re tired of platforming a quick drop back to the level select opens up a couple of areas to visit, with the biggest being the town that somehow exists inside the snake. Slumptown has a number of semi-friendly creatures selling all sorts of things, from extra characters to dress-up items for your slime. There’s even an arcade with a selection of games, which oddly are in full color rather Slime-san‘s limited palette. Slumptown is fairly expansive, with five main areas plus a few offshoots to explore, and the secret exits from the main levels add more characters to its population. These are actually guest-stars from other games, including the developer’s own Wing Diver and Rainworld’s Slugcat. Each character found comes with a coin, and the arcade’s games cost three coins each, so not only is it fun to get a few familiar indie faces spicing up the weirdness of Slumptown but finding them makes the game grow larger.
The coins are only for the arcade, though, and buying anything else costs apples. Each single-screen area has an apple in it somewhere, rarely hidden but always hard to get. It’s hard to clear a level and leave an apple behind without feeling like a challenge was left undone, and most of them only require a handful of deaths to figure out. Slime-san has infinite lives, spawning instantly back at the screen’s start with no down-time, but death resets the screen including the collected apple. The challenges are short but require pinpoint-perfect control, and most of the time the game provides it. There are, unfortunately, a few bugs that haven’t been ironed out quite yet.
A game like Slime-san lives and dies on its controls, so when a character can’t complete a level because it can’t push a block and instead falls into it, getting crushed between block and wall, that’s a problem. When space is thin between sections Slime-san can actually embed itself in the wall, which isn’t supposed to happen. Thankfully it pops out after a second, although sometimes on the other side. The most consistent control issue is in the gravity-reversal areas, which frequently throw off momentum. Trying to dash or jump in there works as expected a fair amount of time, but nowhere close to always. Jumps and dashes end up shorter, and the border between rightside-up and upside-down can be maddening to escape from if you don’t head into it at good speed. When Slime-san acts like it should it’s a top-notch platforming challenge, but certain obstacles are more unreliable than a game with speed-running options should be.
When Slime-san works as intended, it’s an incredibly clever platformer, filled with endless challenges that constantly come up with new riffs on its themes. Its controls are tight and the levels take advantage of this, relying on the precision that comes from a simple move-set to make levels that are incredibly tricky but not unfair to get through. The built-in Twitch integration should be a lot of fun for streamers, especially when putting together a speed run, and the New Game+ levels guarantee there’s more than enough content whether watching or streaming. They may need to mind the language, though, because if there’s one thing Slime-san excels at it’s making the player curse the screen with ever-increasing enthusiasm and creativity. Phasing to jump through a green wall onto a platform that only appears when un-phased and then into a wall that disappears when phased so you can collect the apple embedded in it, then back onto the un-phased platform, is linguistically inspiring. Slime-san is a game with dozens of tricks up its sleeves, each one more devious than the last, and it’s never short on creative ways to put its piece together.