Desperately climbing away from an all-consuming ooze doesn’t sound like a jolly good time, yet somehow, White Knuckle makes it ruthlessly addictive. Thanks to extremely tight controls, a slew of challenging-but-fair obstacle courses, and a dystopian world so bizarre that I need to know more about it, White Knuckle has completely devoured my past few days. And now, like an estranged uncle in a cheesy horror movie, I'd like to rope you in as well!
Easy to learn, hard to master
At its core, White Knuckle is an astonishingly simple game. You can jump, you can sprint, and you can grab onto things with either hand in order to climb. If you're feeling particularly spicy, you can even latch onto ledges with both hands to hoist yourself up faster. What you can't do is hold on forever as your titular white knuckles will quickly start turning bright red, thus warning you that your stamina is running out and that your grip is about to fail. To avoid a grizzly fall you'll need to either find a perch to rest up on, or if safe haven is nowhere to be found, alternate between each hand to buy yourself just enough time to crawl to safety.
Video version of this recommendation (~12 minutes)
If you find yourself in a situation where progress looks impossible - or if you spot a potential shortcut - you can also use one of your limited items to create new handholds on the fly. And considering how this usually involves hurling a piece of rusty rebar straight through thick, industrial concrete, I wouldn’t be even slightly surprised if it turns out that the player character is actually just Popeye. It would certainly explain how he replenishes his supernatural strength by shotgunning cans of what I can only assume is concentrated spinach.
And that's pretty much it as far as the mechanics are concerned. Yet despite how simple it all is, there is a lot of depth, complexity and skill expression to be found here. And more importantly, a lot of fun as well! Once you get into the right rhythm there's just something mesmerizing about swinging from handhold to handhold, making snap decisions on when to expend stamina jumping and when to take it slow, or just throwing caution to the wind to take a supremely risky shortcut purely for the hell of it!
But it's when you get put under pressure that White Knuckle, or Sweaty Palm as it really should've been called, becomes truly transcendent. When there's danger all around you and you're desperately trying to survive the onslaught just so you can get a tiny bit further than you've ever been, that's when the magic happens. In these moments I find that all rational thought evaporates from my brain. I seem to enter a sort of fugue state where the only things that exist are the next few handholds and the obstacles preventing me to reach them. Everything else just kind of fades away until I reach a safe space where I can finally relax, take a deep breath and savor my victory - but only for a brief moment as there's always more to climb!

Procedurally generated levels... or are they?
It's not just the movement mechanics — the level design is also rock solid despite being somewhat procedurally generated on account of White Knuckle being a roguelite. The way it works is that each section you approach draws from a pool of hand-crafted 'levels' with a couple of elements randomly added or removed in order to make them more replayable. Sometimes this means you'll have to completely change your strategy as there's a nasty enemy in an unexpected place; sometimes a pathway you're used to might become more treacherous; and sometimes it might be as simple as you getting a few extra items to incentivize you to take the faster, riskier routes.
The downside of this approach is that you'll eventually see most of the variations, especially in the first two zones as you'll be frequently climbing through them to get back to the much more difficult later stages of the game. The upside is that all of the areas are actually designed and tested by human beings which means that all of them, and I really do mean all of them, have a solid flow and work well with White Knuckle's mechanics. So as far as I'm concerned, these light roguelite elements are implemented really well - they add just enough spice to keep each level fresh, but without actually detracting from its quality.
And quality is exactly what they are, as each individual chunk seems purpose-built around celebrating a certain mechanic or obstacle type, which makes each one feel unique even though they're all industrial nightmares. For example, you can ask any White Knuckle player what they think about the ventilator room with the button... and chances are they'll instantly be able to draw a rough layout from memory. The individual levels really do stick out, and I think a big reason for that is that they're all at the center of at least one story of glorious triumph or bitter failure.

Don't try to pet the ooze. It does NOT like that.
Another aspect of the level design that I greatly appreciate is how clear and obvious the pathways are. Unless the room you're in is intentionally cryptic to get you to make your own routes with items or by using the environment, each area in White Knuckle does a pretty good job of guiding your view towards the next series of obstacles you need to conquer - all the way to the very top.
This might not sound like a big deal now, but when you're frantically climbing away from the grey sludge of doom devouring everything below you, knowing where to go - and how to get there quickly - becomes very important, very fast. Oh and speaking of the sludge, that... uhh, thing, essentially serves as a timer to encourage you to push forward and utilize momentum to your advantage over simply playing it slow and safe. It's terrifying when it's right behind you, and I've messed up plenty of times because I panicked in its presence, but as far as world-ending eldritch horrors go it's actually quite alright. You're never under that much pressure, so once you've gotten accustomed to the movement mechanics you'll only ever have to deal with it when you screw up really badly, which is still preferable to simply getting annihilated and sent back to the start menu.

Sometimes you can actually meet some 'friends'!
Challenging but fair
That said, you're still going to get quite familiar with the start menu. While White Knuckle is generally extremely fair with its challenges, it does not shy away from presenting you with some truly devious gauntlets. I'd like to think I'm fairly experienced with its mechanics at this point, and even still I find myself dying in the second or third zone because it's so easy to slip up, panic instead of salvaging the situation, and then dunk yourself directly into the carnivorous sludge.
However, while it may be punishing to the careless, White Knuckle is not cruel. The challenge ramps up relatively slowly, and all of the crazy trials you'll have to best later have very clear roots in the fairly easy levels at the very start. So just by trying and failing you'll put in a decent amount of time into practicing the basics. So while it might seem annoying having to restart every time you kick the bucket, the process of learning how to speedrun those first few sections is exactly what will make you better at tackling the wildest hazards White Knuckle can throw at you.
There's only one exception to all of this, and it's essentially my only real complaint with White Knuckle. When you're climbing and you jump you'll expend a fair bit of stamina in order to leap upwards as you would expect. But when you do that near an incline there's a chance you can just launch yourself backwards which is almost guaranteed to be a run-ender. Whether this is just a mechanic I don't understand or a bug, I have no idea, but even though I've learned how to work around it I still don't like how jarring and unnatural it feels, especially when the rest of the game is so buttery smooth.

With time, even areas you find tricky will become as easy as a Sunday stroll
The nightmare that is reality
While it's easy to overlook it since you'll be hard-focused on trying not to lose your grip while climbing, White Knuckle has a really surreal and surprisingly compelling world. The visuals, the audio, the screen effects - all of it gives off this grimy, dirty, dystopian atmosphere of true hopelessness. Nothing ever feels right. Even when you reach areas that have been untouched by whatever calamity has befallen the facility it still doesn't feel comfortable, or like a place where you can rest. Instead, it feels more like a facade - something hastily slapped over a gaping wound in the universe in the hopes that not looking at it will make the problem go away.
The story is similarly incomprehensible and mostly comes from environmental clues and the occasional announcement message, but there's enough interesting elements to it that I'm slobbering to learn more. It's obvious that some kind of experiment went wrong and now there's an apocalyptic sludge rising from below, but what in the world are those ungodly noises that sometimes emanate from above us? Is the sludge the reason the facility is collapsing or has the collapse simply enabled it to escape? Is the beast above us a completely unrelated experiment that also went haywire? Are we one of the experiments? I have no idea, but like I said at the very beginning, I am desperate to learn more about this nightmare that White Knuckle calls reality.

Closing thoughts
The final, and perhaps most important note, is that White Knuckle has only just released into Early Access. So while it already has an immense amount of content - and polished content at that - it's not even close to being finished. And in an era where Early Access games can release straight up broken, that really is quite impressive.
So if everything I've shown you thus far has piqued your curiosity, I would heartily recommend you give White Knuckle's demo a try on Steam. It spans the game's first three 'sections' and offers way more gameplay than you would expect, so it should give you a pretty good idea of what the full version is like. Enjoy, and I hope you end up losing yourself in it just like I have!