1 - 250 Kills
– Place a Gatling or Machine Gun Turret in the following three locations before the round starts: Top, Middle and Bottom so you’re facing all the entrances at once.
– Upgrade your Gun Towers once the cash is available, then looking two squares back, place another Gun Tower so they’re covering the gaps in the current setup. This forces the Fieldrunners to - nearly - all run into the same place.
– Place a Slow Tower beside each of the top and bottom Towers so you’re catching those units that run into the middle of the map.
– Once you have $30 combined, replace the middle Gun Tower with a Spark Tower as these are perfectly suited to this map and this setup. Upgrade it and aim to have replaced the first three Gun Towers with Spark Towers before your 250th Kill.
251 - 500 Kills
– You’ll want a few Gun Towers covering the very back of the map to pick up any stragglers who make it through. You can of course booby-trap the exit with any items you may have brought along.
– The trick now is to upgrade all Spark Towers and place a couple more of them near the pathways as you’ll be surprised just how many units take the dirt paths still.
– If you happen to have unlocked the Pyro Tower, then placing it in the middle will reap plenty of points related benefits.
501 - 750 Kills
– Placing Spark Towers at the top and bottom entrances will deal significant damage to units coming from here, making it a mere mop-up job for the centre towers.
– The combos should start building up really quickly, so if you find many units breaking through your defences (or you spot loads appearing for a new wave), then hit the Airstrike as it won’t take long to rebuild and you’ll have a nice wad of cash to spend now.