This could be a long one, but ill try to keep it short and might reference all the new movies
Characters
The first thing that springs into mind are the boring characters, none of them have any personality. You have the Mary sue character of Rey, that out of no where turns out to be the most bad *** Jedi in the freaking universe, an amazing pilot, even though she have never flown a spaceship before. She without any problem whatsoever fixes the Millennium falcon without ever having been on it before, not to mention her flying it good as Han solo in the first movie as well. Even Han solo can't fix it, who have owned it for I don't know how long. No problem for Rey. She orders and correct Ciabatta around the ship like she owns it, despite him having flown around with Han solo for a very long time, so he is demoted to be her side kick. Out of no where and without any training or any background she learns to use the force, even though she don't believe it actually exists. She wins over Luke in a sword fight with no problem, I mean freaking Luke!!! If you look how difficult it is for Luke in the original (Real) Star wars movies, how long it takes him to learn how to use the force, even with while being trained by Yoda himself. Not, Rey takes her a few minutes and after that she can almost move mountains of rock without any problem. She is evenly fighting against Kylo ren, again without any training. And also if you notice she actually have to translate what Ciabatta is saying, Luke have known him for ages and perfectly understand him, and how on earth have she suddenly learned to speak Wookie?
Luke have been completely butchered and turned into a freaking self sorry, sad excuse of a man, who have been fighting his whole life to save his father and make him return to the light side, because he believed it were possible... and what is the lame reason given for his state? That he sensed Kylo ren turning to the dark side, even though Lukes were in fact able to return one of the most evil characters in Star wars back to the light side, and instantly give up with Kylo ren. If that is not enough, its his freaking nephew and no hard feelings between Leia, Han solo towards Luke. That Luke instantly give up on Kylo ren, is to completely kill Lukes character from the real Star wars movies.
Kylo ren is probably the most boring, sad, crying, childish excuse for a bad guy ever. Completely uninteresting all over the place character.
The you have the only sort of interesting character, Snoke who is apparently an extremely powerful Sith, who tells Mary sue (Rey), that he have played her and Kylo ren against each other and know exactly what were going to happen. But for whatever mysteries reason, he is unable to sense that Kylo run is turning the freaking light saber towards him, and is just instantly killed. What the hell was that? Then it is followed up by the most weak fight ever, if you try to look at the fight a few times, you will see how awful it is. Bad guys just standing there waiting for there turn, even though they could cut them down as easy as possible.
There is a lot more to said about the characters, but to keep this short
But what you end up with, having gone through all the character is that Ciabatta is actually the most interesting character left and you can't even understand what he is saying, and they have even made him look ridiculous as well with all those (commercial) pingvins that constantly have to be on the screen whenever he is.
Spaceship
In the real Star wars movies the Rebel uses Y-wings as there primary bombers, however in the new ones they use bombers like they were something out of WW2, completely weird design, where they have to get on top of their target to drop their bombs...seriously?
Also for some unexplained reason, in the second movie it is apparently possible to hyper jump a spaceship into another. Which makes you wonder why they didn't do that in the beginning on the movie and also why they didn't just sacrifice a few drone controlled ships in the Real Star wars movie to take out the Death star. But that isn't enough, it also render Rogue one utterly irrelevant of why they need to steal the plans for the Death star, just hyper jump a X-wing into it or a couple. Even more than that, any future space combat they make, will never make sense again, as you will always wonder why they don't just do that.
The Force
So all mystery around the force is gone, anyone who wants to use it, can apparently do so. Leia is shot into space to use the force to return to the ship, are you kidding me? She is not trained as a Jedi and space would kill her in so many different ways, that it is just ridiculous. For some reason Luke have stored plans in the droid so he can be found, yet when Rey find him, he won't help her... I mean it makes no sense.
Yoda out of the blue appears and is suddenly able to use the force to set fire to things, I mean why didn't obi wan do that in the Real movies? So the force just changes to whatever is needed, without any respect to the lore.
Luke passing a ring to Leia before he goes out to face Kylo ren, how the hell did he do that, he weren't there... well doesn't matter we just change the force. And then he suddenly die sitting on the island, with no explanation and no honor to his character. He weren't even man enough to face Kylo ren in person... seriously haven't they watched the real movies?
And you could go on, the movies are so bad, that its a miracle that the stories that were written weren't discarded straight away.