These remind me of SMB3.
Reviews for "NES Backgrounds"
6th and 10th are my favorites
You definitely have talent when it comes to pixel art since you've been making art in flash throughout the years. Mad respect to you.
All of the backgrounds look incredible! It's difficult to choose which ones are my favourite, but if I had to choose, i'd go with #3 and #8. Great work overall!
The bamboo is my favourite of them but I really like Purple sky as well. Nice stuff Matt!