Oh cool that looks like a level from the sonic and knuckles collection.
Technically, this Tileset was inspired by "Alice in Wonderland/Alice through the Looking Glass" and all I could find for Forests and Mushrooms on Spriters Resource was:
New Super Mario Bros. (flowers and mushrooms)
Sonic & Knuckles (mushrooms, vines and terrain)
I left the terrain from New Super Mario Bros. how it was and did recolour from Sonic & Knuckles to make it look more "colourful".
I was going to remake Allegia Gardens from Wario Master of Disguise, but I couldn't find anything and went for those instead.
Note: Set 3 will not be out by the end of the month, as I can only do 14/15 levels at max. The reason for this is that the poll result to decide the rating won't end until March 1st, as the chosen rating also tells which special level will be in it, but if you want me to end it, since the poll results are the same to last week, let me know(this will also remove this topic completely).