I'm looking for a movie that was set in the US, and all the characters (including the robot) spoke English.
I can't recall the exact plot, but mostly it was about an innocent game robot that shoots small objects for fun and becomes dangerous, because its AI made a wrongful choice about 'winning the game'. The robot starts to arm itself with more dangerous objects (not sure but knives and stuff) and starts to attack people.
It was overall supposed to be fun and adventure movie for kids. Color movie, and probably made in 80~90's.
There is a recurring scene when the robot detects an aggressor, it scans and loudly announces "enemy one, enemy one". The robot was somehow looking similar to Wall-E, and had a saucer-like head part.