Video Game SpaceChem (PC) (2011)

SpaceChem (PC) (2011)

Example of setting up a circuit.
Relevant Links:
SpaceChem Page (Zachtronics Website)
SpaceChem (Steam Store Page)
SpaceChem (
SpaceChem (PC) (

SpaceChem is a puzzle game where the player creates circuits that combine elements together to form compounds (like O2 or HCl).

I've played this game before, logging 5.1 hours into it on Steam. According to my screenshots and backed up save files, I last played on 20130403 from 2AM ET to 7AM ET. Booting up the game with this save file, I find that I only completed four levels. My goodness, I spent five hours on four levels...

Level Select Screen.
Of Pancakes and Spaceships and Slightly Different
Cycles Optimized: 107 1 7
Symbols Optimized: 116 1 6

I previously achieved 137 / 1 / 16.
In my try for Cycles with just Blue I got 277 cycles. So two of those would probably be 137. Yep. Two cycles with some adjustments to the interior gets me 137 cycles.
Cycles Optimized: 137 1 40
Removing one of the cycles, and ignoring the limitation on cycles, I achieve the 16 symbols.
Symbols Optimized: 297 1 16

Another puzzle.
While I initially thought I could do better, 16 is probably the minimum. You need to create and output two different atoms, so 4 for two INs and two OUTs. Each area needs a GRABDROP, so four more. Then to get from beta to psi you need UP and RIGHT. Then to get from alpha to omega you need DOWN and RIGHT. If we're using red and blue, then we get a minimum of 16, because of the necessary return trips. If we use only red or blue, then let's try to have a single RIGHT. This means the path from alpha to omega and alpha to psi unite and there's no way to diverge back to psi / omega. Thus we have to have two RIGHTs. What about getting back. Getting back from psi is one LEFT and from omega is another LEFT. Same argument that the LEFTs must be distinct. And then the same arguments to argue that there are two DOWNs and two UPs. Therefore, while there's a bit of handwaving, to me the minimum is 16 symbols.

What!?! I just found out you don't have to GRABDROP, but you can choose to just GRAB or DROP. That changes things! Damn. Haha.

You can choose to just GRAB or DROP.

An Introduction to Bonding
I suspected it before, but there's an asymmetry in the start times for red and blue. Given two simultaneous cycle actions by red and blue, red will happen before blue. This level was much easier to swap red and blue than in the other level.

Out of a configuration that uses two straight lines, one red and one blue, I get 122 1 12. But I suppose if I'm going for least symbols, then I should just use red. To which I do achieve the minimum.
Symbols Optimized: 192 1 10

Assignment Complete!
Two INs, one BOND, one DROP, four directions (four directions for three locations of in and out is optimal), and one OUTPUT. Finally, a GRAB is necessary to bring the beta to the alpha for bonding or vice versa.
Cycles Optimized: 87 1 22
Making a small change, and switching red and blue (ugh, stupid) I was able to save a cycle. Lol.
Cycles Optimized: 86 1 22
Interestingly, two straight lines is a median wasted time of 5, while two squares has a median wasted time of 4.5 (= 9 / 2).

Today I played three levels and spent 3.6 hours doing so. Oy. Haha. I really should just play through the game without trying to optimize.