For those gamers who never played the original or newer PSP title,
Mercury Meltdown Remix's goal is to guide your mercury to a specific tile. The more mercury you have on the field when you end the level, the better off you are and the more points you have. Where the first game pretty much just restricted you to making sure you had the right colored mercury blobs hitting the checkered area, this game also lets you change the state of your liquid metal to make it harder or runnier.
These three states drastically change the behavior of your mercury. For instance, changing to a colder state will keep your blob together better, thus insuring you will keep more of it by the time you reach the end, but it moves a lot slower. Meanwhile, the hotter state causes your blobs to move faster, but they are much looser and harder to control. The final new state is solid. Here your blob turns into a hard ball bearing and you use this to ride along rails, but of course, if you fall off the edge, you will lose all of the mercury that is in that ball.