Grades for new movies to be released tomorrow on DVD

21 (2008) What might have been a complex story dealing with greed and high-stakes betrayal among the young intellectual elite in America’s gaming playground is instead treated as a slick, glossy romp. Grade: C

Duck (2007) Writer-director Nic Bettauer hits upon some important themes, including homelessness, environmentalism and the plight of the elderly, but not enough care has gone into developing the subsidiary characters who merely come across as types. Grade: C

Heartbeat Detector (2008) Here, knowledge and understanding raise more questions than they answer, and the film ends not in closure, but in openness. It is precisely those qualities that give "Heartbeat Detector" its epic sense of humanity. Take them away and you’d be left with a leaner but markedly less compelling workaday workplace thriller: "Michael Clayton" with Nazis instead of lawyers. Grade: B

The Last Winter (2007) Like his "Wendigo," Larry Fessenden’s latest film has a lot of mumbo jumbo about ancient spirits revived and angered by human disrespect — the old Indian-graveyard paradigm, as clunky as ever. But the context is overpoweringly eerie. Grade: B

Towards Darkness (2008) Antonio Negret’s sloppily executed film plays like a car commercial and a military-recruitment promo. Grade: C-