The Quebeckers have a very special kind of humour. They have a lot of comedians, though there are just about 7 million people in the belle province. They like a lot to laugh, but for someone who isn't a Quebecker and doesn't have their style of humour, it can be very hard to understand or share their jokes.
It's the same thing here. The series was a quite original parody of the Star Trek series with some weird Quebeckers discovering new planets and saving the world. While the first movie of the series had still its original and funny moments and made people feel happy who missed the old times of the series, this sequel is absolutely unnecessary.
The characters are living from there ancient reputation, there are no new elements, there is no interesting story and any surprising element. The directors may have thought: "Well, everyone liked the series and people like to live in the past, so let's make another movie and make some money with it." But sometimes, legends should stay asleep and shall not be waken up, because this movie is just destroying the ancient charm.
I've never seen a movie with so many childish, silly jokes that are not working, it's even worse than ridiculous stuff like "Epic movie". As the jokes are really poor, one also realises that there is a very poor story behind it all, while the first movie is hiding this element with a few interesting jokes, some ideas and some nostalgic elements.
I know so may Quebeckers who like this film. I think that I'll never understand them. So, if you're not one of them and if you're not forced to watch this sequel, just avoid it and maybe watch some "Spaceballs" instead, it's way better.