OK, so the first movie was fantastic and the second was alright. This, however, is everything that made the Simpsons bad. Completely random jokes, a completely random story line which makes no sense going from one thing to another, and what seems to be a lower production value than last time. It's just completely random. Like any recent Simpsons episode, it has nothing remotely funny about, consisting only of lead characters loudly shouting puns or other predictable jokes - because apparently when a voice actor shouts their lines or over-voices them with no hint of wit it's meant to be funny. I reckon the new Simpsons writers got to the script, because it's honestly awful: they've over-spoofed it as well, with white castle, Lord of the Rings and Star Wars all being pointlessly featured.
The main feature of the movie, the alternative world, was only shown for half an hour to make room, instead, for a sub-par story about Professor Farnsworth trying to create an energy crisis in response to Mom increasing the price of fuel. (Yes, it even looks bad on paper.) Not only does the plot make no sense, there is nothing clever done with this poor starting material, meaning there is no redemption in the jokes.
Compare this to the first movie, Bender's Big Score, and this is a travesty of an excuse for entertainment. Bender's Big Score had hilarious jokes, clever writing and an interesting plot which seemed to flow together; heck even the second film at least followed from one theme to another. This is just a mess and dishonours the Futurama name. It's the first Futurama cartoon I've ever not liked, and I hope this isn't the sign of things to come. Stick to the first two movies because this is utter trash.
The ending is also utter garbage, with clear evidence that the (poor) writers couldn't think of anything to conclude the story. Compare this to the brilliant ending of the first movie, where we see Fry's realisation of his future relationship and we find out the person in love with Leela was Fry all along, this just stops the flow of the movie by ending on a lame joke. That's all the explanation you get - one single, lousy joke.
To its credit, the side story with Bender going crazy was mildly humorous, but seemed a lame excuse to thrust the characters randomly into an alternative universe. A huge disappointment to what started out as two excellent feature-length movies. It has ended in an unfunny and completely random cartoon, just like the Simpsons right now. Here's hoping they fire the Simpsons writers they clearly employed and get back whoever wrote the first movie. And if they are the same writers, shame on you for making this. Find ONE plot, stick to it and make it witty. Please don't throw in loads of movie references, jump around the story or make cheap jokes. I'm hoping the last movie in this series is more like the first two.
One last thing - the ratings on here have been given by fans who haven't seen the movie - that's usually what happens, as we make the presumption that every piece of Futurama animation will be brilliant, but don't let the rating fool you. Watch the movie yourself decide for yourself if it's garbage or not.