WE MAY have seen the best of ''Oscar'' in its trailers. The film becomes amusing a half hour or so before it is over, but the first hour is farce that never quite makes it. It is far more frantic than funny.
It's a shame. Sylvester Stallone had probably hoped this film would allow him to break away from action films, but he'll have to try again.
Based on a French play by Claude Magnier, ''Oscar'' presents Stallone as Snaps Provolone, a 1930s mobster who tries to go straight after promising his dying father that he would.
Stallone tries, and so do all the other performers, and that may be the trouble with the film, which opens at area theaters today. They all try too hard and the material can't take it. With dialogue and situations this slight, it would have been better to have approached the script with caution. Material this thin is better handled with delicacy.
Instead, director John Landis (''Animal House'') has everyone yell whenever he or she is on camera. The actors all try, in vain, to make something of a script that just wasn't meant to be done this loudly.
Like all farces, this one is busy with sub plots -- one centers on Snaps Provolone's daughter, who wants to get out of the family mansion so badly she will marry anyone to do so, beginning with the chauffeur.
Another sub plot involves a different young lady pretending to be Snaps' second daughter, a girl who hopes to marry Snaps' accountant.
Want more? There are others, but they amount to very little as the film makes its way, threatening to wind down at every moment.
The casting may be one of the more interesting things about the film. The lineup includes Kirk Douglas as Snaps' father, Yvonne DeCarlo as his aunt, Don Ameche as the family priest, Joey Travolta, Eddie Bracken, Vincent Spano, Ken Howard, Ornella Muti, Tim Curry and Linda Gray. Curry gets the most laughs as a professor of languages.
It's nice to see all these people, but it would have been so much nicer to have seen them under more propitious circumstance.
* Snaps Provolone, mobster, tries to honor his father death bed wish, to give up crime.
CAST: Sylvester Stallone, Peter Riegert, Yvonne DeCarlo, Don Ameche, Eddie Bracken, Vincent Spano, Ken Howard, Ornella Muti, Tim Curry, Linda Gray, Kirk Douglas.
DIRECTOR: John Landis.
) RUNNING TIME: 105 minutes