I have been both a follower and a fan of the Mercury games since they first released on the PSP, and as a result, I've played pretty much every version of the game that has been released. Given that, I am very pleased to see Mercury Hg. Not only is it a whole new slew of puzzles for you to solve, but there are enough new features to make the game feel like more than just another sequel.

Mercury Hg's visual style returns to the more realistic look of the original game, rather than the cel-shaded cartoon-style of the Meltdown titles. The shiny blob is even more stunning this time around though as it comes through great in high-definition. The rest of the game, like the levels themselves and the GUI, all have clean lines and sharp edges that really makes the game's overall appearance pop.

The game's audio has an interesting twist this time around. Basically, the game's visuals react to the beat of the song that is playing. Background elements will pulse like a sound-visualizer, while tiles in the level itself will strobe to the beat. As a result, the whole level really seems to come alive. To make matters more interesting, you don't have to stick to the house and techno music supplied with the game. Even if you play one of the songs on your system, Mercury Hg will react appropriately. While "Custom Soundtracks" isn't a feature boasted about all that much since we left the old Xbox game system, it is rare to see a game actually use the custom song you are playing. This was a nice piece of polish that makes the whole game come alive.

On the surface, Mercury Hg looks and feels like any other game in the series. Your goal is to get as much of your metallic blob to the finish tile as fast as possible, but Hg throws a few new twists that will give even long-time followers of this series some head-scratching puzzles.

All of the standard obstacles are here. You will have to carefully slide your blob across the level without losing too much over the edge. You will have to split your blob up, recombine them in other areas and, of course, the classic color-based puzzles are all still in place. There are some newer obstacles that add to the complexity of the game, the least of which is a set of floating magnets that will either repel or attract your mercury blob, thus making it harder to navigate around the maps.

There are three gameplay modes in Mercury Hg: Discovery, Challenge and Bonus. Discovery Mode puts you in level after level of increasingly more complex puzzles, and it is here where you will unlock the extra levels in the other two modes. Each level in Discovery is named after an element on the Periodic Table, and each collection of levels corresponds to a group on the Table. As you work your way through levels and collect atomic pickups, you will unlock new groups and you will have more levels on the Periodic Table to work through.

You also unlock challenges as you progress through the Discovery Mode. These are small collections of puzzles that you have to tackle one after another, and with the same ball of mercury, so any lost in a previous level is still lost in the next.

The third mode, Bonus, starts you off with a small blob and vials of mercury scattered across the level. Not only do you have to make your way to the finish line, but you must also have collected enough mercury along the way to actually activate the switch. This was an especially nice twist on the standard gameplay found in Mercury Hg.

The Mercury series has always found a good balance when it comes to difficulty, and Mercury Hg is no different. The early levels will only have one or two perils in them and will often show you a new trick or problem, but it isn't long before the game starts combining the different types of obstacles to make more and more difficult puzzles to work through. As a result, the game starts to feel like a cumulative test where mastering the early fundamentals is the key to getting through the much harder, later level arrangements, and with a level for each element, you can expect a ton of levels, each one harder than the last. This is definitely one of those games that you will enjoy only if you truly enjoy problem-solving a tough issue.

Like the rest of the game, Mercury Hg doesn't try and fix the things that aren't broken. The controls are tight, and the only real control you have is the tilting of the level and some control over the camera. That being said, there is a new button to throw into the mix this time around, or at least, I wasn't aware of it before. Basically, if you find your mercury ball has been split into several, then you can hold the (A) button to have the pieces start rolling back together. The only real consequence is that it will eat up some of your time, so use it wisely.

Any fan of the previous games in this line will definitely want to try out this one's puzzles. They grow into a solid challenge and there are a ton of levels to play through. If you haven't played these games before, but like physics-based puzzles games, then this is a good game to jump into and try it out on. You won't be disappointed.