Dodgeball. What could be a more fun activity on ice as a way to work out some of your aggression in a relatively safe manner, while also practicing some skills that might somehow be useful in a game. It would be relatively simple, have people set up on either side of the center line, and placing some balls in the middle (but now actually on the line, otherwise someone is going to lose some fingers when they are reaching in for the balls. And then they are off! It would be an interesting way to work on agility, awareness, and timing as they try to pelt each other with rubber balls. It is safer than actually hitting people or some more aggressive drills, while also making it for a fun change of pace. For goalies, they have to be hit in the chest or else it doesn't count because otherwise that just wouldn't be fair. No headshots allowed!