I think I've beaten all the difficulty levels. I think the person who had problems with some jumps didn't know about the fact taht you can jump very high with some vehicles.I've beaten Low G man on every difficulty with never any problems like this. However, the super-difficult bonus difficulty level I have not beaten. I did get to the last boss and pummelled the ever-living shit out of him and always ran out of time....and this is without even allowing Low G Man to miss a single possible hit....in other words I hit him as many times as was humanly possible on that difficulty, with no room for another stike, and there's just not enough time. So, as far as I'm concerned, the last boss on that difficulty is probably impossible. And seriously, I was REALLY fucking good at that game, and could never beat that last boss on that difficulty. Weird.