| Prototype
                            Differences | 
                  
                    | The option for three speeds has not been
                        implemented yet so the right difficulty switch does
                        nothing.  The game only has two speeds. 
 | 
                  
                    | The Bonus sound plays at a
                        lower pitch. | 
                  
                    | The buggy explosion Sound is
                        different | 
                  
                    | The sound for shooing a rock is different | 
                  
                    | When you fail to get a Bonus,
                        there is no sound or text displayed. | 
                  
                    | The word Bonus is still off
                        center. | 
                  
                    | Instead of showing 1P and 2P
                        for one or two players, this version displays one car or
                        two rover symbols. | 
                  
                    | The level and player select
                        text will sometimes turn white instead of orange after
                        pressing select. | 
                  
                    | The left difficulty switch for music on/off is
                        reversed (A=off / B=on) |