Edit: I have now played Kami for a substantial period of time, and my esteem for it has only grown.
You should probably spend more than ten minutes on a game before you recommend it, or write a review, but I never do what I should probably do, and I'm not planning on changing that just now.
Anyhow... the game is a basic math-based puzzler, albeit a spatial form-based game as opposed to numeric form-based endeavor, all the same - if you like thinking, this game is fun. And if you are not sharp, it is likely fun, too, it just may take a bit longer to progress, but the game design allows for revision, so it ultimately teaches everyone up to the same level. I love it - as a mathlete, and as a fan of creative gaming.
Best endorsement I can say: I bought two more copies of the game within ten minutes of playing it, to be gifted to my girl and my brother. As a purchase decision, it is that easily a no-brainer, despite the cerebral content within. I hope you enjoy it as well.