The hammy acting that brought the worst out of even Ewan.

The continuation of Anakin being made a totally crap character with no believable or reasonable actions towards his generally relatable goals.

The Jedi being pretty oblivious. Palpatine being too obvious.

The poor direction.

The continued over-reliance on CGI. “Oh but they used more models than ever bef-” That’s great, but they still used way too much CGI overtop of everything.

The beginning of the undermining of Vader as a character with his first “noooooooo”

The continued horrible love-dialog between Anakin and Padme.

The battledroids getting stupid voices.

Ugh, I’m sure there are more, but I haven’t seen it in a long time now.