Recently received a batch of LEGO and it contains numerous green bases and attachments for them. I’ve never seen anything similar before. Does anyone know what they are?
Those are Sports Field Sections 8 x 16
They appear in soccer sets
The sets are playable, you can move minifigs on springs to "shoot" the ball, or defend with the goal keeper minifig...
These belong to the Football subtheme, the parts are specificially Sports Field Section 8 x 16 with Horizontal Slot and Black Sliding Holder, Assembly and Sports Field Section 8 x 16.
The smaller black parts are called 4142816: Chair Ø20Mm, Spring Function and were used to have the minifigures kick the ball.