[Fieldrunners 2] Dryer Straits Heroic Perfect + $681 Left!! (No sell, No items)
Well , Like in Bizarre Bazaar . You'll use Ice towers anyway. But I've find some cost efficient slows which can bring down air units pretty easily. It's our good old glue tower.
You can watch this until R53 and then just go AFK for 17 rounds straight and you can still perfect this really easily.
With this setup you can get the Mr. Moneybag achievement too!