I'm with @Mihalko here. A few nice new things, but in general the writing went down. Characters and dialogues became weird, untypical / out of character, and cliche for American series. I can wait for another season and I don't need closure every season, but I feel this is becoming a lot like Lost.

Hm, very enjoyable series but (SPOILER!) closing the story down with how it has been all inside his head was a bit childish.

I thought the series has grown a lot. It started out as funny, but the characters grew in depth and the humour got darker, both of which I liked a lot. Excellent unexpected twists and turns. Looing forward to the next season!

Story was good, but the storywriters really need some help in character and dialogue. Most characters stayed one-dimensional, too many cliches (waiting till a little past the last moment to do anything really, that really gets really annoying). I doubt I will watch season 5 after this.