See it if you like whodunnits...as told by an unhinged protagonist. Well acted, but lots of tangents which slow the pace. Not much substance.
Don't see it if you are annoyed by a manic narrator. Monday is a thriller/character portrait without much takeaway. The actress is better than her material.
"Part of what makes this a compelling story is that its ambiguous clues and its misdirections rope you into sympathy with a character that it might otherwise be hard to find common cause with. Stockton presents Nikki’s unraveling under pressure with sensitivity and subtlety...Austin Pendleton directs with a light touch...Together they offer an opportunity to detect the humanity and pain in the kind of character we would generally prefer to keep at a distance."