Two Mario faces usable for really anything. But I'd say it works best for bonus games. There's a cheerful face with a peace sign, and a disappointed face. There's not much to these. Just the ExGFX file, and the palette. The rest of the space you can fill with whatever you want. Bit wasteful to not, eh?
Solid attempt and looks overall nice, but I'll have to reject this graphic because of some issues involving pixel art.
The first noticeable issue is that Mario doesn't look happy in the "cheerful" face. Its important that a graphic convey well its meaning. Looking far, it looked like sad.
The second issue comes from the limited space to work with. In result, the M in the cap can't be drawn properly. Don't be afraid to use more space if you need it. It will make possible for you to detail the face of Mario a bit better. It will also give you a chance to polish the shading. Lastly, the gloves look off in the shading, as mentioned by one of the comments.
You're almost there, just do the necessary changes I've mentioned, then I can accept the graphic. Good luck.