The fascinating thing about peggle is that there is very little skill involved - i mean it feels like there is, but things go random so quickly.
You are always delighted when things turn up good, it's like a surprise win. And it's not at all frustrating when things go totally pear shaped, because frankly who could foresee that?
Add to that some very slick crafting of the game, achievements etc. and it works as a fun little game