edit: guess I spoke too quickly, that was v3. In v2 the game loop in Phaser is more aggressive detecting "spiral of death" scenarios. Still, the idea is that if your CPU just can't deal with the given number of updates per second even when skipping renders and other "optional" stuff, then there is just no way to avoid a bad experience, either very low framerate or slow motion. Variable framerate simulations can be quite dangerous and unstable, and the example doesn't even try.
edit: guess I spoke too quickly, that was v3. In v2 the game loop in Phaser is more aggressive detecting "spiral of death" scenarios. Still, the idea is that if your CPU just can't deal with the given number of updates per second even when skipping renders and other "optional" stuff, then there is just no way to avoid a bad experience, either very low framerate or slow motion. Variable framerate simulations can be quite dangerous and unstable, and the example doesn't even try.