Boulder TD 4

Boulder TD 4 is the 4th sequel to Boulder TD. It is a remix of Boulder TD3, which in turn, is a remix of Boulder Tower Defense. It has a drastic upgrade from Boulder TD 3, like archers and a ballista.It is the predecessor to Boulder TD 5, with the same initials as Bloons TD 5, a very popular Ninja Kiwi Bloons TD game. It features tower info.

Trivia

 * The Ballista is a reference to Forge of Empires.
 * The archers are also a reference to Forge of Empires.