My aim is to make a fast paced game, all the players have an increased walk speed, speed boosts, and powerups. There are two teams, the runner team runs around collecting points while the kill team tries to kill these runners. When a runner dies all their points are lost and when a killer gets a kill they gain a point. And at the ends of the round the killers become the runners and the runners become the killers. There are four rounds in total.
How long should I make a round in order to keep player engagement but also give them enough time to collect points? While also making sure players in the lobby don’t have a long boring wait. Should I change the times depending on what round it is?
From reading the description you gave, I’d say they don’t need any longer than 5 minutes? Not sure. My advice for you is to play-test the game with some friends and experiment with different times. Set the bar high at first, see how long it takes to collect all the points and stuff and go from there.