I found this on Netflix and was interested because of the combination of writer/director Gareth Edwards and star Iko Uwais - the pair that brought us "The Raid," possibly the best martial arts movie of the last decade. This turns out to have been the warm-up: it was made two years before "The Raid," and is somewhat lower key (although it climaxes in a classic bloodbath) and just not as good.
The movie starts with text on the screen, explaining that "merantau" is when a young man leaves home to come of age - and so Yuda (Uwais) leaves his village and goes to Jakarta. There he soon "rescues" a young woman (Sisca Jessica) from a beating by the manager of the strip joint she works at - although she isn't terribly thankful as it also lost her her job. When she's kidnapped for human trafficking, he goes after her. There are fights.
As martial arts films go, this is ... above average. But not on par with the best of Jackie Chan or "The Raid." And if it's going to be this damn bloody and violent, it better be that good.