From Dust
From dust is a god-game that places you in control of god, who is a glowing worm that can gather up balls of lava, sand, water and the occasional explosive tree and shift them around the world to allow a bunch of aboriginals to activate more powers for your divine worminess to allow you to set the tribals on fire and basically make their lives hell for giving you such divine power. Yes, WTF indeed. You might be thinking from that description that whoever made this game was a few cuckoos short of a clock, and you'd probably be right.

The game was designed by a french game studio, leading me to believe that being able to win wars is what keeps most other countries sane. It's been touted as the spiritual successor to the British-made Populous, by Peter Moleneux, which by default makes you wonder whether or not the french mental healthcare system is allowing a few dangerous crazies to wonder their streets than you could technically call 'safe'. That being said, the game itself is quite fun to play.
The 3 trees in the game allow you to either evaporate streams/roast humans , prevent forest fires/drown humans and explode volcanoes/humans. So basically the choice of whether or not to be benevolent is up to you when it comes to trees. The single player game relies heavily on these plants but its unlikely that you will use them in the sandbox unless you want to see just how big an explosion you can make using the explosive variety.
It basically tasks your divine worm with showing those posers back on dune just what being a giant worm is all about. You lead a group of suicidal humans to conquer and populate areas of land that would normally not be tackled by anyone possessing less backbone than a brontosaurus. Initially you are given a few meager powers, like picking up some sand from one spot and putting it in another spot, then the same with water and then the same with lava. You are also given a few useful spells such as the ability to turn the surrounding water to jelly, summon infinite dirt, put out fires and a few other means of keeping your human followers out of the way of fire, lava and floods. By choosing me the humans were obviously the kind that like to play Russian roulette with only 1 chamber empty. Well since they insisted that I was the only one that could save them from the volcano they wanted to go and live under in exchange for the ability to throw lava around willy-nilly I obliged them.
The single player campaign was a good bit of fun for the 5 or so hours that it lasted, you basically just try to keep your little masked minions from becoming a neolithic Japanese-Iceland, mainly by finding ways of diverting rivers or lava flows. Its quite fun and you can make some rather pretty terrain but all in all its not exactly the most amazing thing I've ever played. Its a volcano sandbox, a limited one. You are only really capable of doing 3 or 4 different things, so basically it is no better than universe sandbox, apart from it being quite good looking. Now for a game that is betting its entire appeal on being attractive, this game falls flat on it face. Its a port, it does not even allow you to fiddle with any of its graphics, so its assuming you're okay with it only being moderately pretty, so its basically telling the PC crowd, yes, you have superior hardware, but I’m not going to have anything to do with it, because if the guys in the other crowd over there find out I’m nicer on you they'll get all upset. The space in which you can operate is VERY limited.
The procedural technology in the game is what is most impressive and when I think about how good thing game COULD have been I wonder why the guys making it did not try to take it to the next level. The multi-leveled / flexible texturing stops you from seeing any texture errors no matter how the terrain is shaped. This kind of game technology is capable of standing up on its own as we have seen from the sales of this game so far, but if you were to get Lion-head, Maxis and the studio behind from dust to take their collective ideas for their similar games and shove them all together you will come up with a truly great game. From dust is good, Spore creature Creator was good (I’m ignoring the rest of that train-smash for now), and populous was great and Genewars had a lot of (completely squandered) potential. You add all these together in a single AAA game and you have the makings of greatness. As for from dust its quite fun, its reasonably priced, but it needs more, it needs to be on a planetary scale, with multiplayer and resourcing of some sort. If you can figure out a way to add the amazing procedural technology of this game to the technologies of others you will make something truly worthwhile.
The challenge mode pits your will versus the mental retardation of the villager AI in challenges such as preventing a village from being burned, because its your responsibility to look after people living on a volcano, the challenges are not really that challenging as you are mostly not in control of the people you are trying to save and simply have to compensate for their foot in mouth thinking and procedural path-finding, that finds straight lines to be somewhat of a conundrum.
So by all means, go out, buy the game, play around in it and see what I mean about it not being nearly as good as it could have been. Its a start. Its a damned good start it just needs more Maxis and Lion-head.
Tl:dr Safe, inexpensive fun for the Lava enthusiast. PC version is a bit half arsed and could have been better.