You play as the star of the game... er, a star. Your goal is to collect all of the other stars in the level, and perhaps grab some coins to boost your score along the way. You can move using the [arrow] keys or [WASD]. But you can only meander around so far when you stick to looking at things in the same old way. This is where the power of perspective comes into play! You can click and drag the entire playing field left or right to rotate the world 90 (or 180) degrees. Now, certain aspects of the world that you might not have seen before become visible, allowing you to play the same level in a new way.
With the power of perspective, you can tackle fifteen star-hunting levels that introduce a number of twists, such as enemies that need to be bounced upon, tricked to walking over certain blocks, or otherwise manipulated using your world-twisting abilities. You'll also find partial star buttons that all need to be pressed in order to remove a barrier on a level. Once you grab the quota of stars, climb the finish block to move on to the next level!
There are some limitations to the perspectives that you can take, however. You can only rotate the world in increments of 90 degrees. You can also only rotate left and right, although rotating upward can let you catch a glance of an overhead perspective of the entire level. You also can't rotate into a position that puts your character in front of (or behind) any island or other block. This could come in handy though, as you can freeze enemies put into these positions using perspective.
Analysis: The twist of using perspective to manipulate two-dimensional playing fields in a three-dimensional world is a somewhat untapped genre in the gaming world. It might be a bit tricky to get used to how the rotations effect the playing area at first. Keep this in mind as a rule of thumb: You and your enemies are assumed to be at the foremost position on an island (which is to say, closest to the camera). When you rotate 90 degrees, you will nearly always end up on an edge because of this.
While there's a series of signs that give a tutorial as you play along, it's sometimes helpful to experiment within the game and learn new tricks on your own. Are you having a hard time figuring trying to find a perspective that you can rotate to? Try rotating while jumping to reach higher platforms. This becomes an essential element in later puzzles, but if you experiment a bit, it can be quite useful earlier on.
The world rotates rather smoothly with each turn, but it's sometimes hard to tell if you've moved too far (or far enough). While it might look like you've found a valid "landing spot" for a turn, it could turn out that you're not in a specific 90 degree rotation from the starting position, which means you might just snap back to your original orientation. Some sort of indication that you're aligned with a valid perspective point (such as flashing the edges of the screen) would have been helpful, but without it, it's recommended that you pay attention to any abnormal angles in islands present, or perhaps rotate slightly above or below the horizon to see if your rotation is aligned.
There are a lot of spatial elements in Sky Island to wrap your head around, but when you get the hang of them, you're in for a treat. Each level is designed to make you experiment with different movements to find the correct path to the finish. So go ahead and give it a shot; it's your turn.