2 things ruined it for me.

1) DEXTER built the robots that he fought in the beginning? While he was building them, didn't he realize they were the same ones? Or that he told them to do the same thing they said to him ("Destroy the person who saved the future")?

2) Throughout the show, DEXTER & DEE-DEE had a normal siblings rivalry (putting the lab and inventions aside). The movies tells us that he's willing to kill her?! Come on!