Thank you for the feedback.
When I initially coded the vacuum I didn't know where to put it without adding unnecessary comlication to the game, so I left it only as this 'secret' mechanic. Concerning movement, I didn't want the player to have tight control over the pack, but your suggestion makes me want to experiment more.
Currently I am working on the game feel you wrote about (gif). Though, I never even considered particle effects, since the screenspace is already teeming particles.