TL;DR If you think this is a fast paced action movie, you're mistaken. Also if you don't like killing people, this movie is for you. Trust me it's pretty good if you don't have the attention span of a gold fish.
EDIT: I watched the movie without watching the trailer. Just saw it rn and i have to say that the trailer represents the movie rly badly lol. I can see why people feel robbed.
Other people may not like it but that's rly down to personal taste. I wouldn't really say thriller in the sense that its full of action. The movie builds up on suspense for most scenes. I'd compare the action or "thrillerness" of the movie to something like hereditary is to horror. It's slower and more methodical, keeping you in suspense instead of putting jump-scares in your face every 5 minutes.
Story was good ig. It had a good premise and set up. The opening would make you mistake it for something similar to Rambo. I don't mind that it doesnt go straight into action. The movie certainly pays homages to its inspirations.
Also, I like how this movie does some extra stuff to make it stand out from all the murderous action heroes. The main character's background ties in really well with his character, how he fights, and chooses not to kill. Although the reasoning isn't that deep imo i'd say it makes sense in retrospect.
Regarding the no killing part, this would be a neat "action" movie to watch if you dont want to show explicit killing to let's say, your kids. I remember watching action movies with one of my grandmas and she'd say it isnt nice to watch them due to the violence, mainly due to the killing.
So, if you're looking for a rambo/borne mash up with a slow burn style and a pacifist protagonist, this movie is definitely for you.
P.S. I don't really understand the reviews dunking on the film regarding the action, i mean it isnt what they were expecting but it doesnt necessitate 1 star and calling it trash lmao.