Cool game, so far I've played for like 30 minutes, the game is easy to understand, and it is really fun clicking all the buttons. So far reached village/forest locations. Will probably update this comment as I keep playing the game.
Also I was initially a bit afraid of that external "download" button, but it is actually really convenient that the game is playable on mobile, can play while commuting in the metro.
Btw, what's with that "share with a friend" and get 200 gold thing? Is gold some micro-transaction thing or what?