One of the indie game that has called the attention most over the last few years has to be World of Goo, a very interesting game in which it is necessary to build structures using a drag and drop technique.
One objective: reach the pipes
In World of Goo the objective is relatively simple, you have to build structures to negotiate the different types of obstacles you will encounter so that as many balls of goo as possible manage to reach their target pipe.
Through out the different scenarios, all of them with different themes and musical ambiance the player will be able to find different kinds of balls of goo to build the necessary structures, be it a tower or a pyramid to reach a tube that is on the ceiling of a cave or a bridge to avoid falling off a cliff.
The game's graphics are simple, but the effects when you drag the different balls of goo are really spectacular and they have also managed an incredible veracity level in what regards to the effects of the laws of physics on the structures.
Download World of Goo to discover this great game.