When I originally saw the video for SpaceChem, I was intrigued. I also read some great industry press on it over at Rock, Paper Shotgun. So I did what I usually do, and picked it up when it went on sale, in this case this summer during the Steam summer sale. I found the game to be alternately extremely enjoyable and mind-bendingly hard, sometimes both at the same time. Unfortunately, at some point a few months back, I hit a wall that I can't seem to get past and the difficulty curve has overtaken my desire to finish the game. That does not, however, mean it's a bad game! I got plenty of enjoyment for my gaming dollar and am more than happy to have had that proverbial gaming dollar go to developers who made something so uniquely interesting and fun, even if I lack the resolve to play it to completion. (I am apparently in good company. Of all the people who have purchased the game on Steam, only 2% of them have finished it!) Despite having never finished it, I do recommend the game. If you get as much enjoyment out of it as I have, it'll be worth your money. Who knows, maybe unlike me, you'll have the ingenuity and resolve to finish it!
RPG notes: The SpaceChem reactors would feel right at home in any number of near- to moderate- future sci-fi settings, and in fact, the atomic-level synthetic chemistry feels like it would be a great addition to a posthuman space-faring setting like Eclipse Phase. The reactors and waldoes have a very "modern CPU architecture" feel to them to me, so their presence in a hard sci-fi setting wouldn't be jarring to me at all.