Can't believe that they rebranded it and didn't go with All Your Need is Kill. But yeah, underrated movie. I think they slightly missed on the ending, but really smart and well-executed movie regardless.
Regarding the ending:
Spoiler!
If they had switched roles at the end and Rita made the final kill and then looped back to before the battle (rather than Cage), it would have been a more impactful ending. Cage would have never had all the experiences that he had that changed him as a person, and Rita would be left wondering if he would ever become the man that she had come to respect, giving us a much greater appreciation for the massive change that his character had over the course of the film. The film has an absolutely fantastic moment in it where we've switched over to her prespective, but don't realize it (when they're on their way to the farmhouse, and we, like her, think that this is the first time we've made it that far, but Cage knows they've been here many times, but never further), and ending the film with her getting looped back would have completed that arc perfectly.