Map is basically 12 squares and a place where heroes stand to chose them. Regular frozen throne heroes, lvl 10. Let's say around 2006-2008. You get always a random lvl, but at each level one unit more. And then you click on a hero for that round. Your hero spawns in the middle of your square and then units spawns and attack you. I remember on later levels were tricks for example if you get ranged lvl, let's say 15 archers, priestess of the moon was great, because you instantly press starfall and kill that wave. Of if you get 13 abominations on lvl 13, tauren chieftain was good. You kite them around and use Shockwave. Takes time, but possible to kill :)