I've saved 91 frames of this game from the first 3 levels alone:
http://tasvideos.org/userfiles/info/57837876123405795
stuff that was improved on was better jumping optimization, it's best to press b about 2 frames after pressing c as your jump wont slow down as much.
I've also found that you slowed down a few times to avoid enemies when you could very easily shoot them, such as around frame 2320.
also when jumping to grab a ledge, you want to jump for the shortest amount of time you can so you dont waste time trying to fall.
at the end of level 3, you duck for a bit to avoid an enemy's projectiles, but I found that if you delay the screen a bit, you can make it so you hit that enemy before you can shoot him again.
this wip syncs all the way to the end, the only differences are what I changed in level 1-3, everything else is Juarez's inputs, which work on bizhawk.