I give it a three. The controls are solid, everything works and the music great.
The only setbacks for me are the lack of originality. The Goombas looks like simplified clones of...well Goombas. The same for the Koopas. They all just have happy faces instead of unique designs to set them apart from what they are based on. Furio, or Mario, looks like he's naked and a bigger nose with a smaller mustache.
You've got a working game; what I suggest you do is make an original idea and apply different graphics on it to make it more appealing. Still, continue on! You've got the skills!