Divide players into even teams of 4. One team starts on offence and one starts on defence. The other teams are on the baseline waiting to come in. Points are only scored by stopping the opposition. Defence stays in as long as they keep stopping the offence. Each time the offence is stopped a new team comes in on offence, trying to get on defence. On a score offence becomes defence, defence steps out, and a new team becomes offence. The game continues in the half court until a team reaches the designated score (whatever the coach chooses). Offence needs to check the ball every time they come in with the coach.

Man to man defensive skills.

If the offense shoots and misses, and the defence gets the rebound, they can take it on a fast break to the other end. If they score on the break they get an extra point and stay on defence. If they do not score right away on the break, that team stays on defence, and a new team comes in on offence. If on the fast break the team turns it over, the series is over and they lose the point they just gained from the rebound, they stay on defence and a new team comes in on offence.
Focus on the offensive aspects of the game, instead of so much on the defence. Have a time limit, and the team with the most points at the end is the winner, the others owe you some conditioning.

Emphasise the importance of communication on defence. Emphasise the importance of staying low and bending your knees, not your back. Teams standing out are ready to come right in, the second the ball becomes dead. All four people crash the boards. Get on the floor after loose balls. Emphasise defensive intensity. Have a coach standing under the basket calling fouls and possibly directing teams. Teams keep track of their own scores, or if you have enough coaches designate a coach to each team. Look at defence, offence can do whatever they want as long as they focus on their skills, and give their teammates good competition.