Wow Thank you. 

I was just playing Streets of Rage the other day and thought someone should do it in Pico8... This is just a mock up I did quickly... However I am working on a beat-em-up game but its in early stages at moment.

Thank you I will revise the art soon, That was also bugging me the outlines in the lighter floor tiles. Thank you   

It's pretty rare to see demakes of older games :D Are you going to make an entire game of this, or are you sticking to just a mockup?

Overall I think this is a pretty strong mockup, but I think there's too much contrast in the areas of the floor that are lit up, since you kept the black outline. It creates a lot of visual noise that distracts from the characters, and makes the character outlines look rather odd when the floor lines line up with them, as well. I think using one of the lighter colours for the outline would work better. Here's a quick edit using the dark grey instead of black.