You have to download Winrar and extract the files. You will see that there is something called "Viva Project" or something of that sort in the files you click on it and you can play the game.
As you can see all versions above 0.5 are in .rar files, this doesnt make any difference for downloading other than the decreased time required, if you want to open said .rar files, use BreeZip (thats what i use and it works fine) and just extract the files to wherever u want to put the game...