Great concept, frustrating execution. It's wayyy too easy to get gold, but usually it's rather frustrating, since you have to get EVERY SINGLE block, no matter how remote the block is on the screen....
Though it's no more original than any tower defense, it's gameplay is amazing and actually addicting. Whereas I leave and return to other tower defenses, I've been trying to finish this game for a month.
To anyone finding this games insanely challenging, I have two tips. Firstly, SLOW DOWN. Trying to do the puzzles quickly results in your screwing up and thus having to start over. Secondly, if you can, go to an older computer. They have less precise controls and the time lags a bit then.