My game of the year for 2017, is a puzzle game which, on top of having no 'correct' solution at all to its puzzles, expects you to look at your own solution and say, "no - this still isn't good enough". Your first answer is almost always an inelegant, brute-force monster that gets the job done; over time - both looking at the field and in your moments away from it - you can tame it, turn the hammer into a scalpel by trimming its size, stripping its parts or reducing its movements to the bare minimum required to complete its very specific task.
My game of the year for 2017, surprising absolutely nobody who follows me on Twitter, is Opus Magnum.
There's a story to Opus Magnum, about a young alchemist working for a noble house, mostly insulated from its political troubles, but you don't need to click through its dialogues to start solving a puzzle - the conversations that tell the story are almost literally a sidebar next to the game interface. For most of the game I didn't realise there was a story; I was too busy jumping into the next challenge - or more often, back into the same challenge over and over again trying everything to shave a few precious cycles off my solution.
The game's presence on Twitter piqued my curiosity, as other players shared hypnotic, impenetrable gifs of machines whose inputs, operation and purpose were impossible to discern. I understood, at some level, that it was a programming game - the developer's pedigree includes SpaceChem and Infinifactory - but the brassy, steampunk aesthetic and the alchemical theme appealed to me immediately.
I'd also been playing around with code golf, an exercise in reducing an algorithm to the shortest number of characters necessary without inhibiting its function. (My favourite result is a random level generation script in 140 characters, which I'd been tweaking for nearly three months.) I didn't realise it until, out of curiosity - mostly about how these machines are made, and more importably controlled - I bought and loaded it up, but Opus Magnum is basically code golf the game.
When you've solved a puzzle, the game shows you three histograms, indicating where you sit on the bell curve in each of three metrics: the area required for your machine, the number of cycles it took to complete its goal, and the cost of the parts. None of this matters - there are usually several puzzles open at a time, completable in any order, and as soon as you've solved a challenge once it's checked off and you can move on.
Except, if you're the kind of person who'll finish one puzzle and move immediately on to the next, this might not be the game for you. Opus Magnum is about obsessively tweaking, refining, adjusting. My favourite times with the game have been rebuilding a machine from scratch because I'm convinced that I can improve it, only to discover that a minor miscalculation has made it three cycles worse.
What makes it work, as an experience, is its machines' predicability. Once I got to grips with the basics of the system, those gifs that had mesmerised me on social media took on a whole new meaning; I could appreciate the effort behind them, understand and adopt their ideas into my own efforts, transmuting strangers' engines and my own into something entirely new.