Juju is fair. It's your job to keep the battle from going close up. He has to keep it close and if you keep going far, he can't do anything about it. It's these tricky ultis that take some time to cast when not in the face of noobs
4/5 because
1. boss difficulty easy>med>hard>VERY EASY
2. shield is better than laser power up
3. no progress bar to tell when boss is coming so i don't know when to get rid of my laser and get shields instead