The First Level is a Terrain introduced in the 16.7.0 update.
It appears to be a cube block that has grass from the top and dirt from the bottom that are more pixelated. It looks a bit similar to the grass ground of the game Super Mario Brothers.
Apparently, it has no use and is just used for cosmetic purposes.
Arcade game themed. It appears to be based on Super Mario Brothers.
- It is presumably based on Super Mario Brothers.