“A children’s musical with a budget of about $25 million! One wonders how many more of those we’ll be seeing. But frankly, recession might bring artistic relief. It’s not that “Shrek the Musical” is a disaster. Not at all. Given the givens, there’s a lot to admire and enjoy. It just can’t sufficiently relax into itself. Its source material lays too many traps. And the world has changed beneath it.”