I had no idea this movie existed, was on prime looking for something to watch and this came highly rated.
The first thing I learned about this movie is that Luc Besson wrote the script, so the immediate expectation given the casting is for some sort of violent, absurdist movie with a strong female lead. Besson is from my limited experience known for either wacky, polarizing space dramas, or gritty, vengeful, lethal femme fatales...this movie is most definitely the latter.
It's very similar to the Professional plot-wise, except we're dealing with a grown-up and not a kid in this movie. The action sequences are very well done and fairly logical for the most part so there's not a need for suspension of disbelief. There is also an absurdist element put in, where as a kid the main character wants to, well, become a Professional, and her mentor just pulls out a gun and starts shooting people to make a point, that she needs to do this smartly otherwise she'll not last very long...a little weird given her mentor lasts quite a while but whatever, anybody used to a Luc Besson script will likely appreciate absurdist elements like this.
I've seen Anna and the Professional, and this movie is right along those lines, so if you liked those movies you'll like this one too. Zoe Saldana plays a very good lead in this movie, so don't expect some sort of miscasting like Valerian. Not the best Besson movie but nowhere near the worst, I think the charisma of the lead helped quite a bit in making this enjoyable...some of the action sequences were stand-out.