very nice looking mario clone!
and in my opinion it’s no problem at all to create a mario inspired game.
now you’re asking for crazy ideas, huh?
the physics is a good start to set that game apart from the original. maybe there’s more to add here? platforms floating on water, trampolines, pinball-bumpers (in general, some sonic-style tubes and bumpers would be nice in a mario game 
you maybe heard of mari0, the mario-portal-mashup http://stabyourself.net/mari0/ – it’s always a nice idea to mashup games – you can also grab the mari0 sourcecode, it’s written in LUA
– it also has a level editor, which is a great feature to bind a community to your game.
you could also try to create new sounds that reminds the player of the original game but are not the original sounds.
you must(!) try SFXR -> http://www.drpetter.se/project_sfxr.html
(there are also linux, mac and iOS ports available)
and… do you have boss fights? I always loved those big screen filling mario bosses.
however, keep us posted. this looks like a nice project!
-finefin
EDIT: I just noticed the link to the AS3 version of SFXR on your site. so you probably already use it 
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