In one way, the isometric viewpoint is a bit of a hindrance when it comes to two-dimensional block-pushing. It can be difficult to work out exactly where tiles are in relation to each other, particularly when there are obstacles in the way. But, I mean, would you just look at Xenopulse, with its crunchy isometric tileset, its wonderfully purple and blue and green alien world.
There's another issue, while I'm griping: restarting a stage (something you'll need to do often, when you mess up a puzzle) also restarts the brief cutscene dialogue, which you'll therefore have to skip through, every single time.
But the game's quirky charm overwrites that frustration. You play as a humanoid robot doing very important space-colonisation business on an alien planet, business that, more often than not, tends to have you pushing mushrooms and sensitive bits of equipment around. If you've played a sokoban (block-pushing) game before now, you won't be surprised when you're required to plug water tiles, or to shove blocks onto, effectively, pressure plates.
But, rarely for a sokoban game, Xenopulse's isometric nature comes into play as well. Stages have height, so you're not just pushing on a flat plane but in a world with literal depth, in this unassuming, charming, and satisfying to unravel puzzle game.
For more great free experiences, check out our roundup of the best free PC games.