This is a sidestroller, speedwalk, or whatever you want to call it. This is also an improvement to the Submission #2330 of adelikat.
It's 75 frames faster measuring the length of the input file. Here is the improvement list:
I got the mushroom in 8-2 (adelikat did it in 8-3)
I saved 42 frames in 8-3
I got hurt in 8-4, the flying fish segment, got in the pipe earlier
I stoped the input file when I entered my last input, too.
I have also tried to get the mushroom in 4-1, but it was not as fast as this one.
There is no improvement before 8-2 in this movie. You have to kill few enemies to get the bullet earlier. I think the bullet in 8-3 is the closest situation.
Hope you like this movie, and thanks to adelikat and andrew_g.