I joined 2 dimensions in 3:21 with a rank of C! Most of that time was trying to plug the cables in, I'll be honest! I did a lot of waving them around in the direction of where I wanted them to go before finally succeeding.
I should also note, the first time I got the teleport sphere, I accidentally threw it into the pit and then couldn't progress any further. I had to restart from the beginning of the game to get another shot, which luckily landed on the platform I was aiming for. :)