My son and I are attempting to play multiplayer HFF1 via Steam from the same household. The experience is very laggy. In some cases, the players freeze and are uncontrollable. In our most recent attempt, the physics was glitching severely:
https://www.youtube.com/live/xS5mFedkFdc
Our Internet connection is very stable and has sufficient bandwidth. We aren't experiencing this in any other online game.