The art and sound are great. They are very true to the NES.

The gameplay is also very polished. However, its somewhat hard to play on a keyboard so I would suggest using a controller. 

The controls are unusual, which is fine if they would've explained what the controls are but they don't explain it in game. I didn't get to experience much because I couldn't figure out the controls well and the AI for the computer players is hard and I couldn't tell if there was a way to lower their difficulty or damage.

From what I saw, it seems to be a very well done game. I hope they keep updating it and/or get praised for how polished it is.