Trying to find the game was in a restaurant here back in the early 90s.
What I can recall is you played a knight or a warrior or something walking in a castle, dungeon, whatever type setting. It was a 2D sidescroller and you didn't move up and down like TMNT/Simpsons, etc.
One particular thing I remember is getting a power-up that would give you a huge energy shield thing that would appear in front of you (not all the way around).
Really can't think of anything else, figured I'd give it a shot to see if it rang any bells.