This is a solo tower defense for 1-6 players with 60 levels. This map has a huge variety of unique towers, and it also uses a wide variety of abilities (cold, poison, warstomp etc) with some decent autocasting. Definitely will keep you busy trying new strategies for a long time.
Personally I think this map is a little long and difficult. Lvls 1-45 are pretty easy and then lvls 50-60 are insane. However the towers are too amazing not to be seen.