Okuno's direction and Monroe's performance, together, create a simmering anxiety that never really relents.

There are few genuine surprises, perhaps, but there are distinctive elements here which set the film apart, not least the way lack of fluency in a language creates a sense of siege.

A very solidly engineered Hitchcockian throwback.

Watcher is a slow burn that creeps from zero to incinerate, while managing to keep the viewer in suspense.