I played RunTD with 3 other people but mis-clicked and did not share income. So basically I played the map solo. I found a very optimized way to build the towers so they form a good path and can hit the monsters many time.
My strat was to build the path with the basic towers, and once the path was done I sold the towers on key point and did the 1400 tower.
I managed to get to the last level but this lagged too much, couldn't build towers on time, so I lose.
There is a reaper wave that can go on the walls ... so they bugged and got stuck on a point. Leave them there or they will kill your towers + probe :)
One of the last wave was baneling, when they die they explode and kill the towers near. Be fast (if you don't lag too much) and make another towers ontop!