I like PvP so this is good!
One thing that does bother me is when multiple towers shoot at the same time attack sounds overlap each other and result in a very loud noise!
I'd suggest some sort of sound effects rework where you would skip duplicate sound effects from playing on the same frame.
Or maybe each sound effect can have slightly randomized pitch value of delayed start by some small random amount (haven't tried this myself, but could help I think)