Hot Tub Time Machine is as devoid of depth as its title is devoid of metaphorical flourish. That being said, it is mildly funny and more critical minds could go to town with the fact that its happy ending has the hot tubbers content with more money, bigger houses and sexier, more deferential wives. Star, producer and co-writer John Cusack’s career has been much maligned lately, but perhaps this is a period of open-ended exploration for him, searching for projects that please him, if not his fans. Co-star Craig Robinson continues to hold the mantle of comic most deserving of a Galifianakis-like break-out and it’s such a rare treat for Crispin Glover, playing a bell-hop, to get a mainstream platform for his singular charm. Hot Tub is a time capsule for a few actors at a certain stage of their careers.