Polarium is a curious hybrid. It is a puzzle game with a childishly simple premise and a lo-fi aesthetic. It is about flipping black-and-white tiles over, trying to arrange them into solid lines. As software, it is trivial. You get the feeling it would run without complaint on an unmodified Atari 2600.

But. Polarium is also unapologetically advanced and sophisticated, and distinctively of its time. It is a game that could only be played on a Nintendo DS, or maybe on a Palm Pilot. From a distance it looks a bit like a spreadsheet. It could almost pass for Real Productive Work, which makes it an ideal candidate for those long evenings when you find yourself chained to your desk. What your boss doesn't know won't hurt him.

Here is how you play. A big grid of squares appears, some white and some black. You drag your stylus across the Nintendo DS touch screen, leaving a little glowing trail behind you. When you lift the nib and then tap it back down again in the same place, all the tiles caught in the glowing trail flip over. All the white ones turn black and all the black ones turn white. As this happens, if you should wind up creating a horizontal line of one solid colour, that entire line will vanish in a puff of sparkly gold.

That is the premise. It turns into play, and a maddeningly addictive kind of play, in a series of puzzles and challenges. In "puzzle" mode, you begin with a screenful of elaborately arranged tiles, and you have just one stroke of the pen to make them all disappear. At first, this is easy; the few misplaced tiles are as obvious as the gaps in a hockey player's mouth. You know instinctively where to put the stylus down and where to lift it up. The screen sparkles a lot. You feel smart and proud of yourself.

But as you master the simpler patterns and the grids get larger, the solutions grow slipperier and ever more evasive. You stare and stare and stare at the screen, begging fate (or your own powers of logic and spatial reasoning) to please give you a break. The bursts of gold are harder to come by. You take frequent breaks, knowing that the health of your carpal tunnel depends on it. The puzzle mode is slow and deliberative and punishing. You will like it exactly as much as you like standardized intelligence tests.

"Challenge" mode is also deliberative and punishing, but it is not at all slow. It is like Tetris with fewer colours and more thinking. Here, clumps of tiles fall from above, stacked three or four high. You must make them disappear, line by line by line, before the pile grows all the way to the top of the upper screen. After a while you will begin to see recurring patterns in the falling clumps, and you will devise a one-stroke solution for each of them. If you are reckless you will begin to feel smug and clever.

Then your stylus will slip just a little, and you will miss a single tile on the bottom line, and your rhythm will wobble for a moment, and suddenly you will realize that your mouth is dry and your breathing is shallow. You will struggle to eliminate the next chunk as it falls, and you will try to tend quickly to the rogue tile before the next block appears, and maybe you'll manage it and maybe you won't, and no matter how it turns out, you will feel your adrenal glands firing like they haven't fired in weeks.

Polarium will haunt you while you sleep. It will follow you into public washrooms, where you will find yourself unable to stop drawing imaginary lines across the ceramics. It is a simple monochrome game, true, but it is also mood-altering and mind-altering and deeply thoughtful. It is unforgettable.