Thank you for your precise feedback ... I "confess", that at the end, I was running after minutes and had to let some strange behaviors behind me... I was struggled with the param of the plants/roots pop in ... in fact, you're right it seems to be easier à the end than at beginning... I had to fix that ...
For the both behaviors of the switching worm ( i never have the "boomerang one", it could be intresting to code the both and find a system to active one or the other... it could disturb the player...