Don't get me wrong, great game, nice tribute.....all of that. If it IS mafia land, where's the rival gang? Instead of shyguys and Birdo-like creatures, use mafia gangsters (and a big guy with a cannon for Birdo). Now, for the second stage, you added the trap mask (good idea, not really a tribute to the game without him) but, you seem to have made him too godly. He comes after you as long as you have the key, which makes it impossible to traverse the rest of the level. I even had trouble getting out of the room brcause you had to super jump out of there, only to find out he'll be chasing me OUTSIDE of his room. I tried to set it up so that the key would fall with me in the sand pit, but no good, it would just float there.
It's nice that Super Mario Bros. 2 inspired you, but the only thing that has to be the same is the gameplay(controls/character attributes), try make everything else work more towards your title.