Woohoo took forever but got the hard badge! Just keep at it guys! you can do it. Just remember if you jump through a gate in the air you get a speed boost (not tunnles) and you loose the speed of you go though to many gate while on the ground.
Great Game and good Hard badge. I'm up to 75X just cant get back there. Some tricks I found if you Hit a gate in the Air you speed up about 4X faster. so if you can chain jumping though gates you get lots of Multiplier.
The Mad scientist achievement should be a Hard badge. well for me at least I wiped out every city then realized i still had that one to go... so i had to farm this one crapy little city 40-50 times. not pretty
I really havent had all the much Trouble with energy. Just Finish off the Lv by killing some on in teh arena. it will take you to like 12-15% into the Next lv. find the old man and always do triva. just good the answers. i've leved up from 5-20 with 10-15 energy left over each lv.