The full island is out now. Just get a Walkthrough for the island.
There was no demo. There was a game called "Spook Central" that featured a hunt for ghosts on 5 other islands. It was discontinued when the island was released. (see related question)
You find the inventor and get the helicopter. However, you can't ride it.
You could not "beat" any of the demo of the island. The quest stopped when you were shrunk, and you could not go right into the apartment. (see the related question)
Early Access for Game Show Island (island 22) opened on Thursday, October 27, 2011 at 5:20 PM EDT (2100 UTC).General free access followed four weeks later on Tuesday, November 22, 2011.During Early Access, all users were be able to play the Money Ladder mini-game and the demo quest. The demo ends where the player would board the jet to fly to the 5 game-show cities around the world.
No. The Island Map is no longer interactive except to show when an island is in Demo mode (usually during Early Access for paid monthly members). Islands converted to the problematic new 2013 look will be in color on the map.
Considering how the game has not been completed yet (it currently has the eighth demo in production) you can't really "beat" it; only play it.
you can't the demo past if the island is already there but you can play the demo on new islands.
There will be no demo
There is no way to download this game unless you buy the original Zoombinis or Zoombinis Mountain Rescue and download the demo of Zoombinis Island Odyssey.
You can watch a minecraft game demo at youtube or dailymotion.
In the demo for the island, players could look around through the viewfinder overlooking the Loch. Some would see a shadowy shape of Nessie, and win Cryptids costume items. (see related blog link)
*During Early Access, players who were not paid monthly members could only play a demo form of the island. The demo closed with the release of the island on July 28, 2011. The demo only took the player up to the point where he/she was shrunk by the Shrink Ray in C.J.'s apartment. (see the solution at the related question below)