The whirlwinds of warfare

Grandfather and grandson have declared a war over a bedroom. Although it's just harmless friendly fire they take it serious enough and the pranks they come up with are thought-out and cool. They've hard time putting down their weapons even at holidays, birthdays and funerals, so there's collateral damage included. Quite silly a movie, but it's good to see people like Robert De Niro, Christopher Walken, Jane Seymour and Cheech Marin letting it loose for a while and do a good old family movie.