Al Pacino, Alan Arkin and Christopher Walken star in "Stand Up Guys." 2012 - Lionsgate.

In this week's new movies, Christopher Walken saves an up-and-down script in "Stand Up Guys" and Sylvester Stallone barely muscles his way through "Bullet to the Head." Here's what the Post critics had to say:

** "Stand Up Guys" (R) "'Stand Up Guys' stoops to conquer, shuffling along at a leisurely gait, hoping that audiences will have the time and patience to catch up with it. Those who do will be modestly rewarded, mostly by the chance to see Christopher Walken work his now-reliable magic with a script that veers wildly in quality and tone." -- Ann Hornaday

* "Bullet to the Head" (PG-13) "A nasty, pulpy, occasionally risible advertisement for its superannuated muscle-bound star, this adaptation of the graphic novel plays it straight when it should wink and careers into chaotic, unimaginative mayhem when it should go long on style." -- Ann Hornaday

*½ "Warm Bodies" (PG-13) "It’s less funny and self-aware than 'Shawn of the Dead,' less swooningly romantic than 'Twilight' (to which it bears strong similarities) and less scary than pretty much anything else out there with zombies in it. Fans of 'The Walking Dead' can keep moving; there’s nothing to see here." -- Michael O'Sullivan

**½ "Oscar Nominated Short Films 2012: Animation" (Unrated) "This year’s Academy Award nominees in the category of animated short film feel notably old-fashioned, quaint even. One offering (Disney’s 'Paperman') is a black-and-white love story set in what looks like 1940s Manhattan. All of the films are virtually dialogueless, telling their stories like silent films." -- Michael O'Sullivan

**½ "Oscar Nominated Short Films 2012: Live Action" (Unrated) "The shadow of death darkens -- and in some cases deepens -- all five Academy Award nominees in the live-action short category. That’s especially true for 'Death of a Shadow,' a ghoulishly brilliant Belgian fantasia about a ghost (Matthias Schoenaerts) who photographs the shadows of people in the act of dying for a mysterious art collector (Peter Van Den Eede). Part sci-fi, part steampunk, part love story, it’s easily the best -- or at least the most original -- of the five nominees." -- Michael O'Sullivan