This took a long time to draw. Here's what I did and followed the moderator's suggestions:
-changed the name of this tileset to an appropiate one;
-all the big barrels act like tile 100 above and tile 25 below and all small barrels act like tile 100;
-horizontal and vertical lasers animate now. I wanted to make them stationary, but that didn't work;
-'hill tripping' is removed now;
-fixed scrolling settings;
-added the moderator's color suggestion and re-organized the BG a bit;
-removed the white sparkles on the BG windows. Some SNES games kept those, but yeah did the change;
-layer 3 BG has been reworked now. Original clouds have been added, some inspiration from SMB3 and the lightning is way better.
If you do use the lightning, then make a custom block with it.