The first three seasons were really interesting and funny. For a long time I did not laugh at so many episodes. However, from the fourth to the sixth, everything changed and the jokes became somehow... flat, with banal toilet humor and overly stupid. No, not "futurama-style absurdly funny in it's style", but simply stupid, like in an episode when a robot took a gun, stupidly shoots all bullets in air for half a minute of the episode, and then complains that the gun is now empty and useless. This is not a "joke that just happened", but "a joke for the sake of a joke, just rudely thrown into the episode, in the hope that the viewer will take it for the style of the series." As a result, these few seasons were completely raw and not funny. And since this was the main highlight of the series, the mottled stories no longer aroused much interest, losing their charm.
Last season was better. Not good enough like the first three, but still better than the fourth - sixth ones. However, the overall impression of the series still remained ... disappointment.
Review of Futurama
