Hey, it's just a cheap quartz movement. If cleaning the contacts for the battery doesn't fix it, get a new movement - probably about $10.
Some clocks are worth fixing - usually depends on the case. Some clocks never need fixing - I've got a Chelsea ships clock (non-striking) that just keeps going. I've had a look at the movement in it, and it looks like it was designed to survive depth charge attack - the rubies on the balance wheel are the size of pencil erasers. I think I'd have to fire a bullet into it to kill it. But, cheap Bakelite case - go figure??
I've got another mantel clock - nice pillar and scroll case. Original movement had wood gears and keeping that movement going sent several clockmakers kids through college. I gave up on the wood gears and installed a modern movement. I wanted a pendulum movement, but getting one with a pendulum length to match the window in the front glass was not successful. Installed a balance wheel movement, and also installed a 'pendulum swinger' that runs off a AA battery and just swings a pendulum - any length you like. Made the pendulum length to suit the front glass, then had to install a 'scotch tape' damper on the bob to keep it from knocking against the case.
CucKoo clocks are another story...