Before you get too excited, know that Cube the game is not based on the 1997 sci-fi film, Cube. Instead, Cube is a puzzle game for the PlayStation Portable that has you moving a nondescript block around 135 abstract levels of varying degrees of difficulty. It's a fine concept, but unfortunately the puzzles in Cube are less a test of your spatial reasoning and more a test of your ability to situate the game's camera so you can see what you're doing. The uninspired puzzles are made all the more boring by the completely lifeless presentation in Cube. Even with the addition of a level editor and ad hoc multiplayer with game sharing, Cube just doesn't do enough to set it apart from numerous, better puzzle games already available for the PSP.
The keys aren't hard to find; the tricky part is collecting them all and getting to the exit within the time limit.
In Cube, you control a transparent cube that can move in four directions, with one side always connected to a solid object like a block. There is no gravity in the game, so you can move your cube along all sides of the blocks that make up the level. The goal of each level is to reach the exit panel, which is invariably tucked away behind barriers or hazards or floating on a distant, disconnected block. It's your job to hit switches that make barriers retract or make new blocks appear to create a path to the exit panel. Sometimes the puzzle is even simpler than that, merely requiring you to navigate a short path of connected cubes to reach the exit.
Many levels have hazards such as rolling mines, quicksand, or moving blocks that will crush you if you aren't careful. These hazards are usually easy to avoid if you can see them, but unfortunately the camera makes that more difficult than it should be. By default, the camera stays behind your block, and you can zoom in or out as desired. You can also press the R or L button to rotate the camera around your block to get a better viewing angle of the path ahead. Technically this works fine, but it's a pain to have to move one space, adjust the camera, move another space, adjust the camera, and so on for each move you make. It can also be incredibly confusing and disorienting to constantly change the camera angle, making it easy to get turned around upside down and backward.
Taking time to adjust the camera is tedious, and it impedes your success with the game. Each level has keys scattered about that you have to collect before reaching the exit. If you collect the keys and get to the exit within a set time limit, you get a gold medal for the level. As a result, every second counts, so while you're trying to make a break for the exit, you won't have time to futz with the camera. The easiest way to get a gold medal is to fail the level enough times to memorize exactly what you have to do step-by-step, and then execute those steps as quickly as possible. Needless to say, that's not a satisfying way to solve a puzzle. That trial-and-error process is also frustrating because when you die, it takes about 10 seconds to reload the level so you can try again.