Wow nice work!
Very impressive! I loved master Blaster and I still do, and i think you definetly captured the feel. The lowering of the tank was a VERY nice touch as well.
Things I would work on is smothing out the background or maybe even creating some of your own original levels, and im sure you know you have to fix them buggies.
Overall, if you made a game with this engiene it will have a high chance of getting on the front page (with Tom being a major fan of anything that is NES) and im sure you will make it into the "game remake" collection. Once again, nice work!