Bombs over Green Hill - good but it needs more drums than just the 8-bit ones! and the chorus is slighty out of sync (i know you probably know this but still)
Kanye Night Zone - nooooooooooooooo why is it edited? and again, this would sound PHAT with Gold Digger's drums!
Knuckles got Seoul - this is hawt...until 1:00 when the other drum things came in from the original source. other than that, best so far!
Crank dat Robo-otnik - fits pretty good, unfortunately it's soulja boy and gets annoying real fast
Fear of ur mom - hahah, yeaaahhhh booiii!
99 Balloons - jay-z sounds like he got a little younger...it goes slighty off at 0:48...and it feels like it stays that way the rest of the time, but i don't know for sure
what u know bout shit - more edited, boooo. and the main melody is kinda yeouch on the ears
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for not usually doing mash-ups, this was pretty good. best in my opinion was knuckles, robotnik, and mobius.
good shtuff