SpaceChem

So you want to know about SpaceChem? Well, the first thing you need to do is survive this next sentence. SpaceChem is a game about chemistry. Still here? Okay, good, because there is much more to SpaceChem than just the chemistry part, though I'm sure that might be too much for people with a very bad experience in that subject.

To be fair, SpaceChem is really a puzzle game wherein the challenge is a to create what is essentially a program to produce some chemical compound. For example, one of the earlier levels lets you spawn in either H₂ or O₂, but to complete the level you must come up with a means of combining the two elements into a H₂O₂ molecule, which is complicated by the rules of chemistry where the Hs can only attach to one molecule at a time, and the Os only two, so you need to break the bond holding the H₂ together, as well as weaken the bond holding the O₂ together so you have room to attach those Hs. So yes, having some knowledge of chemistry helps, but by no means do you have to know that the reason you can only have two bonds on an oxygen is because it has 6 electrons in it's outer shell, and thus has room for two more. That deeper level of information is provided in a much more convenient form via an included periodic table with a simple 2 next to the oxygen, which is more than enough information to play this game.

My solution to break about the H₂ from the top left, weaken the O₂ from the bottom left, and recombine the two into the final product, where it is shipped off on the top right.

If you're not convinced that the chemistry portion of the game isn't important yet, I can't blame you. That's because I haven't covered the mechanics of how you go about altering those molecules, and that's where the puzzle portion of the game comes it.

There are rules that govern what you can do in your workspace, which is inside a reactor. You get two little tools, called waldos, to move things around, and you determine exactly what they will do, creating a path and adding instructions like picking up a molecule, dropping it, calling in more or sending a completed one out. The trick is that you need to coordinate your actions so that the whole thing doesn't blow up in your face, which can happen when you hit the walls, or two molecules collide because you thought you picked something up but didn't, or you try and send the wrong molecule to the output, and so on. Furthermore, you're limited to one instruction per waldo per square, but you can route them over the same spot multiple times through clever pathing or by the use of some of the advanced instructions that add more logic to the game, such as going left the first time a waldo passes over it, but right the next time. By the time you unlock everything, and come to have a good grasp of the tools at your disposal, you'll be surprised what you can make.

This one just repeats a loop until a sensor at the bottom is triggered. The result is far more impressive than the puzzle that produces it.

To make things more interesting, there are a variety of reactors, and while all are physically the same size for the internals, you'll find that some only let you bond molecules, or others only let you break them apart. Others let you fuse two molecules together, such as combing several oxygen until you get some uranium. These are all revealed over time, but come into play most importantly during production missions, levels in which you are allowed to use several different reactors, routing the results of one into the next, until you can ultimately take the raw resources from the left and combine them through whatever processes you deem necessary to get the required product. You may need to place a bonding reactor first so you can break a molecule down into it's base components, and then send some of those off to be fused into something else, which eventually meets back up with everything else in a supper bonder to create some bizarre combination of elements.
 

Production missions also require you to properly lay out your reactors, giving them an extra layer of difficulty. Space is always at a premium in this game.

There is in fact a story to SpaceChem, which is revealed in parts as you progress through the various missions. It starts with you departing to work at for one of the large chemistry corporations, which harvest materials from foreign worlds and stars. Things get interesting when equipment starts behaving strangely, something possesses your boss, and then you ultimately find the facility you're working at comes under attack by a bizarre presence. Though you only gain brief bits of story throughout the campaign, a few pages per world, it does make for an interesting distraction from the otherwise all consuming puzzle portion of the game, and is genuinely enjoyable.

The story also helps justify the boss fights in the game. Yes, boss fights in a puzzle game.

What I like about SpaceChem, from a puzzle point of view, is the simultaneous simplicity and complexity of the whole thing. Besides a few specifics, like those production missions or special reactors, each level is the same in that you always start with the same empty reactor no matter how complex the molecule you need to create is, and it is up to you to come up with a solution, any solution, that works for the task at hand. Rather than many other puzzle games where there is only one, narrowly prescribed solution, SpaceChem gives you the freedom to do whatever you want in that little space, where you can try a multitude of ideas, good and bad, until you finally come up with something that gives you what you want, and where your solution can be drastically different than anyone else. While other puzzle games are hard because it is difficult to come to the single solution, thinking of something like Portal 2, SpaceChem is hard because you have too much freedom, and must work through all those ideas that don't work until you find something that does. Personally, SpaceChem has raised the bar by which I now judge all puzzle games, which pretty much sucks for anything else out there.

A particularly bad solution, as noted compared to others. But the thing is, it works.

It should be noted that I played SpaceChem over quite a long period of time. The game is very challenging, and after a while I would just hit a wall, coming up short of any solutions that would work, so it did take a bit of playing here and there over the course of a few months before I was finally able to beat the game, though my play time only clocks in at 34 hours. There are many who could do much better than that, and I have seen some brilliant solutions, such as one that accomplished what I did in 5 reactors in 1, so ultimately your time to completion in this game will depend on just how good you are with logic puzzles, and if you enjoy it enough, you can always head over to the portion that is full of user generated content for even more to do. The game is normally $10, and I wouldn't recommend paying below $5 for it - to help you decide, there is a demo out there, because maybe you're good enough you can pay more for it. Overall SpaceChem is a brilliant game that will leave you in awe, either in what you create or when you see what other people can do - 10 out of 10.

So, the final breakdown:

Score: 10/10

Suggested Price: $5+