You would play as either Joe or Mac and would have to rescue your four stone age girlfriends while fighting through dinosaurs using lots of different weapon powerups.
My favourite part was at the start where the evil cavemen stole your girlfriends. There were two brunettes (i think they were twins) and a silver hair girl and a chubby girl. Guess who I liked the most
.It was also one of the first games I can remember that had multiple endings. After beating the last boss you had three paths to take and you'd have a different cut scene showing who Joe and Mac rescued after their extreme battle.