Click on a block on screen to interact with it; clicking and holding in the center lets you drag it around, while clicking and holding in any of the block's four corners will let you rotate it. Double click on a block to lift it into the air, and then on the arrows that appear to turn it to display different sides. The goal is to properly assemble the picture displayed at the start of each level, and if you forget, you can click on the bar at the right of the screen to display it again. Correctly matched pieces snap together when they get close. As you progress, the number of pieces you need to work with increases, and so does the variety of pictures you need to sort through to make the correct image.
There's nothing to really make you feel the crunch to finish a level quickly, although if you don't complete a puzzle before the bonus timer counts down you herald the end of the world at the hands of Galactus... oh, wait, I mean, you lose out on a bonus to your final score for the level. Which, while perhaps a little disheartening for those of you who worship at the altar of the high score table, is still hardly a deal-breaker.
Analysis: Man, shhh. Just... chill a moment, yeah? Picture Cubes has a particularly mellow presentation that's about as relaxing as you can get. The visuals are beautiful, the music is soft, and even the sound effects are pleasant. Picture Cubes is basically the digital equivalent of having someone standing behind you and gently massaging your temples. It's got a gentle difficulty curve, and the whole thing is just fun to play.
Which might be a good thing, since the most difficult thing about the game can be dealing with what appears to be a very sleepy physics engine. Everything seems just slightly delayed, like it's happening underwater. Which, you know, is frustrating when your high score sort of depends on moving with some sense of urgency. Thankfully, once blocks have been connected together, you can't break them apart; blocks that are correctly aligned magically snap together, eliminating trying to align tiny pixels, and then to avoid bumping them apart.
Picture Cubes isn't exactly a high-octane experience. (At least not until you unlock the rail gun.) You and six other friends are not going to be huddled breathlessly around the monitor, whooping, high-fiving, and calling each other "brah" every time someone matches a piece. Instead, it's a mellow, relaxing experience that's accessible to just about anyone. If you just want something simple, lovely, and well made to pass the time with, Picture Cubes is just what the doctor ordered.
... I mean, I assume he was a doctor. Sure the certificate was written in crayon, but he seemed trustworthy. Oh, just play it!