Minimalism. This game embodies the idea. From impressionistic graphics to a streamlined verbset of move and jump, this game does away with all unnecessary aspects of design and lets its superb ambiance and atmosphere shine through. I want to say La Monte Young would be proud, but the lush orchestral pieces probably wouldn't be to his liking. I dig them though. I dig this game, and you should play it.
Seiklus and other games based on exploration are muddled with their collect-a-thon hang-ups, but smartly the game takes a page from Knytt and makes discovering its landscapes a reward in and of itself. As you meander about the small worlds, the camera pulls back and you bring light to the area; the more you explore the more beautiful your surroundings get. Saying anything else would spoil the experience, so go and play this thing.
Spoiler-y musings follow:
The protagonist complains at the outset that "there is too much noise." He goes through the ordeal of completing the game to ultimately commit suicide, where he is free of the problems of life and can obtain peaceful "silence." The four landscapes all share the motif of flawed beauty; the city area has industrial sludge perpetually running, and in one section you explore the innards of a dead majestic creature. When playing you have multiple dead ends that prevent you from progressing. These dead ends hinder your progress, but allow you to see more of the wonderful landscapes. It seems as if the protagonist wasn't able to appreciate this aspect of life, and focused on the less appealing bits. To me the game tries to argue the opposite. Sure, there is a lot of shit that goes on in the world, but there is a lot of beauty too. If you pull back and can appreciate it, you can make a life worth living --to throw your life away is foolish. Or something. The story is vague enough to allow multiple interpretations. It's an amazing experience regardless.