to many glitches
that main one that got me going. I fell down a hole, i was constently being spawned over the hole, so falling back into it!
things like that one up mushrooms, they jsut sit there. on the first level they are a normall size, but the nest they a big?
as for the water, lets not even start with that. and the fish... jsut not how they are ment to be.
If you had made your own game, taking insperation from mario, then you can do it how ever you want, but you didnt, you jstu treied to rip it of, and didnt do it well