If you're a fan of freeform puzzles, chances are that you picked up Opus Magnum the second it went on sale, and have tweaked and optimised your way through everything it had to offer. It's a rare breed of puzzle game, though - Zachlikes, as we like to call them - and they're few and far between.
Enter Prime Mover from 4Bit Games. Described by Zachtronics head Zach Barth himself as a blend of Spacechem and TIS-100. Build circuits, solve programming problems, and compare your score against the world using Zach's thankfully-not-patented histogram scoreboards. It's also out today on Steam.
Like Opus Magnum before it, Prime Mover starts off at the shallower end of the brain-melting pool that is truly freeform puzzling. At first you'll just be connecting point A to point B, getting numerical inputs to their required outputs, but you'll soon be escalating to addition, subtraction, complex sorting systems and more. While most should be able to bodge through the problems presented, it'll take a lot of careful thought to end up high on the histograms at the end of the levels, which is where the real long-term joy of a Zachlike lies.
Holding the game together is a strange little story, told through small cutscenes with alien subtitles, seemingly revolving around some kind of techno-fantasy robot civilisation, and your puzzling is helping them get closer to some mythical mathematical artifact of their past. If nothing else, it's an excuse to have the background and borders of the playfield change on every level, which is a nice detail.
This kind of lite pseudo-programming style is a fairly regular fixture in this kind of game. Tomorrow Corporation's Human Resource Machine (and its upcoming sequel, Seven Billion Humans) is quite similar in style, and Zachtronics' own TIS-100 played around with basic numerical input and outputs before cranking up the demands on the player in later missions.
If all this seems a little lightweight, there is still Shenzhen I/O, if you want to start getting into real programming on top of the pseudo-realistic circuit assembly fun. Personally, Infinifactory is just about as far as my brain goes, but I've never really had a head for programming anyway.
Prime Mover is out now, currently on Steam only, and costs £11.50/12.50€/$15.