Exit is a puzzle about rotation rather than movement: you can't control the ball directly, only turn the entire level left or right, and gravity does the rest. Getting the ball to the exit means working out the sequence of rotations that rolls it there.
It's a clean idea executed well — each level has an intended sequence, and the moment you see it the solution takes three seconds to perform.
You don't — you rotate the level and gravity moves the ball. The puzzle is working out the sequence of rotations that rolls it to the exit.
No — it's a thinking puzzle, and you can rotate as many times as you like.
Yes — tap the left or right side of the screen to rotate. Nothing to install.