I quite enjoyed this game.
I really enjoyed playing this, but I have a few tips on how you can improve the overal playability in the next game. For starters Mario moved at an incredibly slow rate. Whenever I play mario I always hold the run button, perhaps you should include a run button. Another problem was the still backgrounds. I think the game would be a little better if it was played as a scrolling background instead of various stages. Powerups would also be nice, and perhaps button sensitivity with the jumping. I look foward to the final version and I hope you take advantage of my suggestions.
-Mopsicle, NG veteran of the BBS