I'm still unsure where this fits in the MCU...
After the complete lack of chemistry between McCarthy and Bateman in Identity Thief, it seems inexplicable that they've been paired together in yet another movie. Just like Identity Thief, Thunder Force is two good ideas for separate movies squished into one bad film.
It suffers from an almost complete absence of jokes - other than that the leads are a bit too fat to get out of a car in a graceful manner. Melissa McCarthy plays the same character as she does in every movie - which is typical of American comedians - she's always fun to watch, but her schtick feels a bit neutered in a PG rated film.
Imagine if this has been played straight - have two middle-aged women become superheroes and try to save their city. That could have been a fun, cartoony, and interesting exploration of superhero tropes. That would have provided a brilliant satire of bloated factory-line franchises.
Or, imagine if they turned it into a full-blooded spoof? Film it like the 1960s Bat-Man, take the piss out of all the clichés. There's a moment where McCarthy is seducing Crab-Man Bateman which is almost like the seduction between Michelle Pfeiffer's Catwoman and Michael Keaton's Batman - but it completely fluffs it.
Instead, we get some lazy scatological jokes, a recycling of Austin Powers' "let's kill the henchmen" gag, and Bateman getting bit in the balls by a crab. Not exactly laugh-a-minute.
Octavia Spencer is criminally underused. She's such a good actress, but she looks faintly embarrassed and bored. Which, coincidentally, is how I felt after watching.