It's beautiful. It's smart. It's fresh. It's funny. It's charming. And it is absolutely original.
The Characters in Botanicula are adorable and in every single way, charming. The main cast consists of a seed, a mushroom, a flee... thing, a large nut(I think), and a walking stick(sort of). Each character has a specific roll to play in your adventure and is utilized in very unique ways. They stick together for most of the game, making funny and cute childlike sounds when excited, scared, or just tired. You are guaranteed to have a smile on your face EVERY time the characters interact with the world, the puzzles, and especially with each other.
The puzzles here are not very hard, but they aren't all that easy, either. The game is split into four parts, each with its own set of unique puzzles, most of which can be completed in any order, with the exception of a few chain puzzles. The majority of them require your characters to interact with NPCs and the wonderful creatures in the world using sequence and timing to activate an event, usually allowing you to grab an item. I quite enjoy the difficulty, it causes you to think a little bit, but never pushes you into frustration and away from the heart of the game.
Botaniculas visuals are outstanding. The hand drawn aesthetic makes for a heartfelt adventure that makes you stop and admire almost more than you will actually be solving puzzles. I second Mark Walton in saying that The way Amanita sees the world is extraordinarily special. The childish heart and mind they have bring you back, in a sense, while allowing you to take in the story and events in a more mature manner. A great amount of work and passion goes into creating something as warm as Botanicula. Every click results in a unique animation, bringing a smile. Amanita's got a knack for that sort of thing.
The music and sound design in this game stand out among almost all of its features. DVA, the band responsible for the soundtrack, ingeniously create music perfectly fitting of the tone of every level and frame. Every character and creature, surface and item(the intractable ones, anyway) make a very distinct and unique sound... again with the smirks and smiles. There isn't much more to say other than the care and quality put into it are superb.
The story of Botanicula isn't a particularly worthwhile one, but the world it revolves around along with the characters and creatures inside that world are unbelievably original and imaginative. It starts out atop a large tree. Spiders come and completely overrun it and wreak havoc upon the trees inhabitants. The five characters are, in a roundabout way, forced together, each struggling to save their colonies. As you work your way from the tree top, to the lower "city" area of the tree trunk, to the root system, you see that the spiders have, quite literally, sucked almost all life on their way up. Your quest quickly becomes clear... bring the tree back to life while removing the spiders.
Botanicula is an especially respectable game if you take into account the massive piracy issue Amanita faced with their first full length title, Machinarium. With less than 15% of the copies in circulation actually purchased, the Czech studio took it hard. Its a joy to see their resilience. Amanita is playing a big part in the revival of the beloved adventure genre and will undoubtedly play a huge role in carrying it in the coming years.
I suggest Botanicula to ANY adventure fan. Its... well I already said it. Play the game, it's worth every penny.