When I first played Super Hexagon, a couple of months before it was released, I didn't like it at all. Yesterday I completed it, in the lesser sense (60 seconds on the first three difficulty settings - I have yet to master the Hyper modes).
Unlike most other media, games demand a response. It's possible to consume music, movies, books, etc. purely as a one-way action; we take them as input and no output is required. Output can be given - we can sing, dance, play music, we can dwell on the meaning of a novel and let it change us - but these are optional; we're not playing a game at all if we don't act. This gives games the potential for stronger mind-altering properties than other media; they force us to contort our brain into new shapes to play them, to reprogram ourselves to be able to give the responses they require. Anything we learn and do alters our minds, but games seem an unusually efficient way of installing new and unusual software onto our grey matter.
Usually you can start playing a game using skills you already have, but to play a good game well requires developing new software. Strategy games piggyback on logical reasoning, a conscious mode of thought, but to play well we enter a state of computation that is not entirely conscious: a beginner at Chess can play passably by simply working out the consequences of each possible move, but an expert evaluates the board with a post-rational mindset, synthesising conscious thought with strange powers of pattern recognition earned through long study. Action games force us into new modes of thought more efficiently because they require responses within limited time; they don't give the option to consciously evaluate all possible moves. (This is why I say that Glitch Tank's real-time mode is superior to turn-based.) Games can be a tool for entering new and alien states of consciousness - but unlike drugs, they operate purely at a software level, using controlled input channels.
Super Hexagon tests the limits of human reflexes and execution, it requires developing the ability to act faster than you would have thought humanly possible. It's most satisfying when you're playing right at your limit, or pushing just a little bit past it. At first it was too far beyond my skill level for me to enjoy it; it was just frustrating. I pushed through this out of respect for Terry; I played it occasionally over several months and eventually got through that barrier, but it wasn't pleasant. I respect the decision to keep the difficulty level uncompromisingly high; an "easy" level would be pointless; but something slightly lower might have made it less painful for me to get into. Or maybe not - just as running or playing the guitar hurts at first, perhaps initial training in such an extreme high-speed action game is unavoidably a struggle.
As you improve at the game, your perception of time changes. Patterns that seemed too fast to possibly respond to slow down and become reasonable, you have time to see the gaps and to move into them. You reach a point where Hexagon mode actually starts to feel slow. Then later you realise that Hexagoner is actually easier than Hexagon; the patterns are longer, so there are fewer of them and you can see further ahead, you can last longer just through muscle memory; and that starts to feel slow too. You begin to ascribe meanings, characters to the patterns, seeing some as friends and some as enemies. You lose consciousness, your brain fully occupied running the software needed to play - then suddenly you regain it, transcending it, able to think and talk while your thumbs keep on playing without needing your attention. You perceive the gaps between thoughts, your consciousness running faster than them. You start to feel that Hexagonest is actually easier than the other two because in those you now have to consciously delay before acting, slow your reflexes down, avoid getting distracted in the long gaps. And then when you finally do complete it, it's almost a let down - it's become so slow as to be unchallenging, and now the Hyper modes are what's interesting. This is Super Hexagon's payload, the new mode of thought it forces you into, the super-power it grants you: accelerated time sense.
Hexagon rides the line between reflexive action and pattern memorisation. Often it falls too far toward the second for my taste; learning arbitrary patterns frustrates me, my initial reaction was that it was a waste of time. But it leavens it somewhat by giving an extremely short delay to get back into the action (a characteristic of many of Terry's games), by randomising patterns to produce varied situations rather than a strictly learnable sequence all the way through, and by obfuscating the patterns through its weirdly spinning viewpoint. So it suffers less from this than bullet-hell shooters do. Still, at its heart the gameplay is a simple call-and-response. It feels like a weakness that it ends up so dependent on memorisation, with no complex decision-making, no long-term consequences other than survival. But it is what it is, and maybe it couldn't have achieved its goals of pushing reaction time so far in a relatively accessible way had it demanded a less simple computation to be performed.