I bought this today because of a recommendation from a Game Stop employee. Well worth the $20.
Great use of the Wii remote (tilt forward, back, side to side) to move the mercury ball around. Yeah, it's basic. That is what makes it great.
This type of game is not my personal cup of tea; but, for the price I figured I would buy it. The puzzles are clever and it is just fun to guide the mercury blob around. FWIW, I intended on just buying Wii Play for an extra remote and casual game to play with the family .. I regret not just buying melt down because it is significantly more entertaining.