This game is just so addicting. The motive of the game has you starting with a preset amount of "goo" in each level. The usual goal is to get as many of the goo valls into the goal pipe. To get to these pipes, you must make a stable structure of goo with the least amount of goo to that pipe as to lead the remaining goo into the pipe. Black goo balls get permanently stuck together in the structure. Green goo balls work the same as black ones, but you can detach them and move them somewhere else. Yellow ones get stuck to surrounding objects and are also detachable. Water drop goos just hang down and are permanent. Dead goo can survive spikes. Red goo catches on fire. Beauty and ugly goo are useless, but the levels they're in usually have them as the main priority to go in the pipe.
This game is also has a few types of goo and other objects, it's jam packed with levels, an OCD rating for each level (which really hard to get), a goo corparation level that has all the goo you've collected to use to build the biggest tower online competing against others.
This is my favorite puzzle game for the PC and is cheaper than most at only 20$