Write a loop that builds the molecule, then make it run leaner every pass.
Program a repeating sequence of arm moves that grabs atoms and bonds them into the target molecule, then runs that loop over and over. Once it works, optimise the cycle to produce more in less time.
Reaction Rush dresses a programming-and-optimisation challenge as a molecular assembly line, blending computational thinking with chemistry.
Programming arms to grab atoms and bond them into a target molecule, then looping the sequence and optimising the cycle, is SpaceChem — Zachtronics' 2011 puzzle game built on automation and chemical bonding, in which two manipulators called waldos are driven by a visual programming language.
Optimising throughput once the loop works is the original's scoring and it is kept here.
Making the program repeat is what turns it from a puzzle into engineering. A sequence that works once is easy; one that works forever must return every arm to its starting state, which is the constraint that makes industrial automation hard in reality too.
Reaction Rush is a programming-and-optimisation puzzle dressed as a molecular assembly line. It's an original, free browser game made in-house for PlayPendium.