Uh, it's interesting. Will you have scrolling levels later on? My main problem was that you mixed sprites. You had an SMB3 tile set but SMB1 characters. And the SMB1 characters don't stand the test of time as well as SMB3 ones do.
yes there will be scrolling levels later.
generally the background will be from all mario games. just so happens this one is from SMB3.
as i develop more of the game, i think you will get on what i mean by "digital upgrades"