It's a solid 5½ easy, if not a 6; certainly deserving a better score and wider viewing than it currently has (3.5 and 294 ratings).
It is confusing but I disagree with the reviewer who believes the 'twist' is given away too early so ruining the 'big reveal' - I suspect the director and writer did not intend a 'twist in the tale' and the confusion is deliberate; and once one settles into the viewing, it works (for me anyway). As it flashes between different settings, I did not know whether other scenes depicted the future, the past or geographically elsewhere; did the events in the main part of the film cause the other scenes, or are they parallel rather than directly related? It slowly becomes clear, piece by piece, like a jigsaw. The ending is satisfying but sufficiently ambiguous to prompt discussion - if only more people were watching and discussing (is redemption possible for all the protagonists, or did one protagonist have to suffer one punishment cycle for their responsibility?).
The acting by all concerned was certainly adequate at the very least (I was immersed in the film anyway, watching the actual characters, as opposed to being brought out of a film by people trying, with no great success, to act).
Also, an effective use of Charles Gounod's 'Ave Maria' (Méditation sur le Premier Prélude de Piano de S. Bach) - scoring a violent scene with soft, slow music can emphasise the poignancy of it (e.g. Oliver Stone's use of Barber's 'Adagio for Strings' as the soldiers destroy the village in his 'Platoon').
One final complement to it: I'm now far more sceptical of low ratings from small numbers on IMDb, and more inclined to give such films a chance.