I'm pretty sure Bigfish is bigger than PopCap. Most game sites mention or redirect to BigFish & they pretty much have every 2D flash game ever made, & just when you think you'd found one they're missing, it shows up a few days latter. They also have 5 buildings in Seattle, if that means anything. Why are almost all game companies in Washington? I could go on a tour of them if I wanted.
I tried Peggle. After 5 seconds I was already bored to tears & switched to Aveyond, whis is listed as a casual game but is too much like Secret of Mana/Zelda/Chrono Trigger/Final Fantasy to be listed as such.