REAL CLASSMENT :

#10 KENOS

#9 ZODIAC

#8 HARD MACHINE

#7 THE GOLDEN

#6 TRUEFFET because this is a pretty short level and there is memory timings not so hard

#5 SONIC WAVE INFINITY because this is an XL level and there is more hard timings than TRUEFFET in the buffed wave part

#4 ARCTURUS because this is hard but short, harder than SONIC WAVE INFINITY because all ship parts in arcturus are "impossible" (extremely hard)

#3 TARTARUS because as you can see, there is hard memory timings and some "world's hardest jumps" in the level and the 2 fly ball parts are really hard

#2 SLAUGHTERHOUSE because this is a pretty "short" level and we can see what we do (not like in firework) and "impossible" wave part

#1 FIREWORK. Aah... Firework... I don't have to say why this is the first but I'm gonna do it : XL, SILENT, WE CAN'T SEE ANYTHING, MEMORY TIMINGS IMPOSSIBL etc.... U know, I don't know how the verifier do it... I don't know why RubRub rate it... Stop to say : "OMG this guy say SLAUGHTERHOUSE is harder than FIREWORK so it's true !" Dorami... EVW... And more youtubers test it... Dorami do slaughter house in 1000 attempts if I remember and firework in 2000 or 3000 att.... OVER !!! FIREWORK IS THE HARDEST !!! And it's not just a little harder than SLAUGHTERHOUSE... This is 2 times...3times...4 times harder than FIREWORK... SO... It's the proof. Subscribe to my channel if you're ok with this classment...