I'm sure a bunch of people did this already, but I will compare this movie to the classic Groundhog Day:
involve the hero living the same time period over and over. (The hero's
name here is "William Cage", and he's played by Tom Cruise.)
He remembers what he did in previous time iterations, but everyone
else is living the day for the first time.
The other main character is a female named "Rita". (Vrataski, played
by Emily Blunt).
Cage starts out unlikeable and cynical, but his character
improves throughout the film.
And Cage's only hope of escaping the time loop is
to somehow learn from his past mistakes, go back and try again.
There are differences, of course. Mainly because it's a cross between Groundhog Day and (the good parts of) Starship Troopers.
Instead of simply falling asleep at the end of the day, Cage gets killed, in invariably nasty (but PG-13) ways: his death snaps him back to the start of the loop. He's in a war against alien invaders, and he gradually discovers he's humanity's only hope against certain doom. So he's got that going for him.
It's a lot of fun. Special effects are super-impressive, but (like Godzilla) too many of them take place in the dark. (I think that's how they save money on special effects.) Tom Cruise, no matter how nuts he might be in real life, remains a very fine actor. Emily Blunt… well, wow. Just wow.