'John Carter' gets a little lost on Mars

“John Carter” is a bloated sci-fi epic made watchable by swell effects, passable performances and those little dashes of humor that reassure us that the filmmakers know this is all a lark – no matter what the budget. It begins as a Western, veers into sci-fi, and finally finds its footing as a blend of those, with a dash of sword and sorcery – a Confederate cavalryman slashing and hacking beasties and baddies all over the dusty, dying Red Planet in the years just after America’s Civil War.