When I was younger, I always wanted to play a game that gave me incredible freedom when it comes to magic, something that didn't give me just a little, set amount of spells I can use, like most games do, but rather a place where to DO magic, to create my own. Years later Noita does that, and much more.
Wand tinkering, and spells in general, would require a review on their own: there are around 380 spells in the base game, and 422 in the current beta branch (UPDATE: Beta branch went live two days after this), and most of them, if not all, are interesting in their own right. The amount of things you are allowed to do is immense. Do you want a wand that casts angry boulders, ready to fly onto any and every enemy they see, crushing them to their death? Not only it's doable, but it only requires you to use TWO spells. Perhaps you'd like a wand that shoots nukes (!) at the same rate a machine gun shoots its stuff? I wouldn't recommend it, your PC probably wouldn't like it, but it doesn't hurt to try once... or twice. Or how about using a spell that kills (read: destroy) any enemy within range (the range being your entire screen) just like that, as if they were disappearing because you've snapped your fingers? Such spell exists.
Of course, some spells are better than others, and some require better wands to be casted, but Noita works in mysterious ways, and with the right set of spells, even the most humble ones can become weapons of mass destruction.
Always cast wands add lots of fun and new ideas to the mix: every time you cast any spell from said wand, the spell (or spells, you can have multiple always casts) will get casted as well. A good always cast spell can and will change your run, although they're fairly rare to come by.
The complexity of wand tinkering is definitely not something that I can fully cover, because even now, 283 hours into the game, I still feel like I've barely scratched its surface; Noita does that pretty well: making me feel like I'm still learning something new, every single run. For those who are interested, YouTube is full of tutorials on how to maximise damage, on which spells you want to look for, on which synergise well... Personally I've always avoided them: spending time tinkering is a key component to MY enjoyment of the game, and sharing the results with some of the friends that play the game makes it even more satisfying.
Alchemy, or as a friend of mine likes to call it, shampoo making, definitely deserves a mention as well, alongside potions in general. Note that when I say alchemy, I am referring only to the act of potion mixing, and not the concept of alchemy as a whole, with all its references to real life (more on that later).
Noita has a big variety of potions, liquids and materials going on, and lots of them interact with each other: from mixing Acceleratium (a liquid that makes you go faster) and Levitatium (a liquid that lets you levitate faster) together to create Hastium (a liquid that will let you both move and levitate faster) to creating an alchemical wonder that will turn everything it touches into gold, alchemy comes in different degrees of complexity. Just like wand tinkering then, you can spend hours upon hours messing around with liquids, trying to conoct something new and interesting while updating a spreadsheet open where you save your discoveries: mixing Acceleratium with Slime isn't a good idea; heating up Water will create Smoke; setting a small pixel of Oil on fire will eventually turn the whole pool of oil into fire; throwing Blood on Lava will create Volcanic Rock, and so on. Chances are I've never seen every single potion in the game, since I've happened to stumble across liquids I had never seen before not too long ago. The current beta branch is adding some more liquids as well, one of which is a game changer when it comes to alchemy, and will make mixing potions easier and more fun.
For the potions to have an effect on you you don't necessarily have to stain yourself with them, since the game also has a drink (and eat) mechanic. Of course, drinking some potions and liquids isn't a good idea (why would you drink your flask of Acid?), but the option is always there. You can also eat some materials. Eating some things in certain quantities might also make... interesting things happen, so go ahead and consume everything you see: if it does you good, good for you, and if does you bad, at least you've learnt something new!
I'll never be able to stress enough the importance of learning from your mistakes in Noita. The whole point of the game is to learn: learn which spells are good and synergise well, learn which potions you always want to have with you, learn which enemies are best avoided, what they do, learn what perks do, and which are best. Exploring the world is incredibly fun, its main structure remains mostly unvaried. You can go down the mountain, trying to get down as much as you can, but it only represents a small amount of the content Noita has to offer. There is a whole world to be explored, filled with secrets, enemies, bosses and special wands. In due time, if you're willing to sink time into it, you'll learn how it's structured, how to traverse it, and where to look for anything that might make you stronger. The artwork is amazing, I am in love with it, and I'm still disappointed there is no points shop: 500 Steam points for a Noita profile background WILL be worth it.
Enemies, bosses in particular, will teach you the importance of having different kinds of damage, since some of them are completely immune to certain kinds, while also being weak to others: is it really that surprising that the guy made out of fire dies when thrown water at? A wand you've made, after hours of careful consideration and hard work to look for the right spells, might turn out to be completely powerless against the boss you meant to fight. And yes, it has happened to me!
Some might complain the game is too harsh on you, and while I don't agree with them, denying it's still harsh would be unfair. The game IS harsh, some enjoy calling it "a great self-discovery tool for masochists". You will die, a lot, sometimes in frustrating ways, through no fault of yours. Sometimes it's so random you'll ask yourself "how am I meant to avoid this?", but you WILL learn how to survive longer, how to avoid dangerous situations, how to heal consistently, how to make the best out of what you have, and "random" deaths will happen less and less. You'll come to hate polymorphine, and enemies that shoot it, they'll make you feel vulnerable even at your strongest, and I like it: you'll never be fully invincible.
There are also some complaints on the game's secrets: even I felt the game might have been too wiki dependant when I first started, since I just couldn't figure out what some things meant, what they did, how to use them, but the game DOES give you the means of solving them (although admittedly a few of them are really obscure). A lot of answers are scattered throughout the world, and when you'll find them, you'll connect the dots, and feel satisfied, and in future runs you'll be able to take advantage of your new-found secret: so go ahead and explore the world, your curiosity is rewarded.
Do keep in mind the game is trying to go for a whimsical, esoteric feel, that rewards people willing to take their time and understand what surrounds them; it has plenty of references to Alchemy and Finnish mythology: the latter I am completely unprepared for, the former I'm lucky enough to know things of. Watching how the game interprets some of its concepts (the Emerald Tablet, alchemical symbols...) has been very interesting. It also even has its own writing system. And some secrets are yet unsolved! Perhaps you'll be the one to solve them!
Try the game out then, give it another try if you've played it in the past, and keep playing it if you've never stopped: the game is a harsh teacher, but learning is incredibly fun.