Weapons such as grenade launcher, rocket launcher, and grenades. It's stupid how you just click and it's an instant hit. Giving them travel time would be much more better since players will be able to dodge them, and they're op when the shooter has a motion sensor.
However I also suggest giving them a damage buff if they get this travel time, and also players will have to predict the enemies movement, so players with skill shouldn't have s problem. Also giving rockets their own characteristics would be nice, like AP rockets could travel faster, do more damage, but has 2 hex splash radius, while explosive has 4-5 blast radius with less damage and slightly slower travel time.