Fancy a bit of quality real-time strategy gaming with robots from the developers of Fat Princess? You should know then that Carbon Games' AirMech is available now on the Chrome Web Store, completely free of charge.
Installation is straightforward -- just visit the game's page on the store, hit the "Add to Chrome" button and wait for the 55.6MB download to complete. Once it's done, it'll install itself. To play, just open a new tab and select it from the available apps list.
You'll need to sign into Google to play, but it's a small price to pay to play this great little RTS. Everything is done in your browser, too. It has a bit of a Transformers-meets-Total Annihilation vibe, if that's your thing and features competitive matches for up to six players, and co-op for four.