him vs giant mom at the end was pretty funny
the "bad guy" in this movie was really bizarre, the guy with shit sticking out of his head was just lame and i kept expecting a reveal that he was being controlled by starro the past 30 years but nope, he's just a guy who likes torturing dogs aliens i guess? all the villain stuff was super lame and needed a massive rewrite, if they really wanted to jam Harley Quinn down our throats they should have made her the ultimate villain who was 3 steps ahead of everyone all along.
But brain guy + bizarre alien + rando generals + freedom fighters + weird ass "creature jail" just was simultaneously overly complicated and super underwhelming. Also SUPER bizarre that Amanda Waller just did not give a single FUCK that a giant alien kaiju was going to take over a nation, that entire subplot of her staff staging a revolt "for the kids" was so shitty. There wasn't even a hint that 30 years of research into Starro accomplished anything.
a version of Harley being the mastermind somehow, rapidly killing most of the other cast and her goal is just releasing starro and causing mayhem is very Joker-esque and coulda been fun. They would not do it I bet though because they don't want Harley to be "derived" from Joker or "evil", which is a shame. James Gunn can setup decent teams but his villains have all been pretty mediocre.