Play boils down to maneuvering your mercury through mazes by tilting the game board itself, making your way from the starting point to the checkered flag with as much of your original supply as possible. Wander a bit too far over an edge, and bits of precious metal drop away into the void. Unlock gates with pressure plates, ooze through paint shop beams for color-coded locks, coax simple-minded sentient obstacles into helping you out, and avoid mercury-gobbling bad guys.
There are tons of different board pieces, from heaters that speed you up and coolers that slow you down, to air jets that launch, paint stalls to add color and flux transmitters that teleport. Your blob can even be turned into a metal marble and ride on rails.
While the difficulty of the original game was uneven at best, Mercury Meltdown Remix ramps up slowly and surely over its exhaustive stable of 200+ levels, and the variety of mercury states and obstacles keep it from ever growing too stale. Each level challenges you to make it to the end with all your goo, finish within a set period of time, and collect all bonuses along the way, and seldom are you likely to achieve all three at once, leading to a surprising level of replay value and general-purpose just-one-more-board addiction.