LOL. The title says it all. Not a lot of gameplay so I spent some time bashing Bob for the fun of it.
Sorry. It seems to me that you missed something. We just put FD on the winning block. And that's all. I think you, as always, have come up with something interesting. I have already tried to shove FD into the tunnel and push through B. But if there is any surprise, then there is no motivation to find out. Because FD is a win. And that's all.
Spoiler The purpose of this card is to show that B will be trapped inside. And the function of FD is to make this card winnable. am I right?
The author does not respond. But I think it's too easy (and he was counting on a different playthrough). I found 2 more ways to win without placing FD on the winning block. 1) Use FD to move B to the winning block - outside the structure. 2) Put FD next to B in the tunnel, pushed under B (so that FD is in front of B), set it to the limit of the invisible part of the tunnel, and B ran through the tunnel to the winning block. I think the "2" way is what the author intended. Very much like that.
I don't know why it worked, but I managed to get the FD into the tunnel and push B through. I'm not sure why B doesn't get stuck when the FD is pushing.