You shoot the ball into one of two areas to lock it and start video mode. In the game you are a caveman in a maze with 5 triceratops. You want to run over all 5 triceratops to reach the next screen. When you run over a triceratops, it will turn into a t-rex, which will kill you (and drain your ball) if it runs into you. There are four exits to the maze which will take you back to the pinball portion and you can keep exiting out of any of them (except the one you started in) at any point - unlike Baby Pac which locks the exits. Back out on the pinball playfield, if you hit certain drop targets you can turn the t-rex's into pterodactyl's, which you can kill for points. You can also make an extra ball icon appear in the video mode. So basically you can go into video mode, kill a few triceratops, run to an exit, hit some pinball shots to turn the t-rex's into pterodactyls, re-enter the video, finish them off, etc.
Also when you run over the fifth triceratops, you will go to the next level and all the t-rex's will turn back into triceratops. Since the t-rex's were chasing you, it's likely they are all now bunched together, so sometimes you can go on big "combos" and pass like 2-3 levels in one swoop if you're fast.
The maze doesn't change with each level, just the speed of everyone and the color scheme.