Kamurai
Really good watch, would watch again, and can recommend.
While this was casted really well and the actors all did a great job, what makes this movie for me is the structure. It doesn't really do anything special, but for that sacrifice they do 3-4 parallel arcs.
For slasher fans, there is a lot of fun here, and the bodies hit the floor all over in a spectacular fashion.
Really trying not to spoil anything, I can only point to a handful of features where there are multiple survival situations in play at once. Its a special kind of intensity that obscures what's going to happen next.
While there is a telegraph of a sequel / series in the title, they do an excellent job of wrapping up the story to move forward to the next feature.