Hey, mariobros12, long time no see!
I've definetly seen these tiles before and they look good to me for the most part. I'm not a huge fan of the colours on the + shaped dirt pattern. In my opinion they're a bit to dark. Maybe it's because you stick to the SMW Palette, which is completely fine, I like to see more SMW styled stuff around.
I also remember you once had a project going with DarkYoshi. What happened to that? Did it ever get inished?
It really doesn't look like a SMW tileset, it frankly seems a match to SMB3. The palette you used was awkward, which makes it seem it came out of a forest. It could additionally use some improvements with the inside, and Sceptrum was correct and the fact that it seems way too gloomy for a peaceful atmosphere. It's good for a start, but has immense room for numerous modifications I believe. Keep on making graphics though, Mariobros12.