Really nice puzzle game. I'm impressed you pulled this off so well on the NES; it plays great and is smooth and fairly polished. The AI is certainly challenging enough for a beginner. I also really like the music, and the art, while simple, looks great. I haven't played the original, but was able to figure out the mechanics here on my own pretty quickly except for the attack pattern, which feels like it requires explanation.

Loved it. Has great music as well. 

I actually never played Puzzle Fighter, so the gameplay was totally new to me. ^^ I like it a lot, and have kept coming back to it. My main feedback is that the green and teal are really close in color, so can be a bit of a strain at time. Maybe choosing colors that also have more brightness contrast between them, or including a unique pattern for each color, could make it a little less reliant on hue recognition? Either way, you pulled this off well. Congrats!

Really enjoyed the AI opponent, seemed a good match for my complete lack of skill, I just managed to scrape through with a few nail biting wins, perfect balance! Music is great, wish there were a few input beeps and such for feedback. Very solid!