Most people would say this anime is hilarious...and it is. I mean, boy gets flushed, becomes king of some weird place, tries to bring justice to the world in some very weird ways. Only, I think it's very good because it's not just hilarious.
Somehow, it's hilarious but also tragic. But not full on crying your head off tragic. It's almost like admist the comedy and the light side there's this dark side seeping out.
The plot takes really unexpected twists and turns. But not so sudden that you're taken by total surprise. You're hinted at it, but you only actually realise what you were hinted at until something actually happens. Although this mainly happens at the end of the anime, where things start to go wrong, which is also when it's most interesting.