This web client is built in WebGL so it is playable on most modern web browsers like Firefox, Internet Explorer, Safari apart from Chrome of course. Google Chrome users however get special Chrome-specific levels featuring Chrome graphics for blocks and bombs. You can choose to play either the SD or HD version with the former tailored for low-end PCs with slow graphics.
The good news is, this game is playable offline once you bookmarked the website and played it once.
Hurry and bookmark Angry Birds for Chrome today before they're blocked by your Network Administrators soon! :-)