Hello, thanks for trying out my game. You can find more information about this TD at http://www.eAlienSoft.com as well as future versions of the game.
Next enemy mode is listed in bottom left of map.
Normal enemies go at a normal speed and have normal hp
Armored enemies go at normal speed and have some extra hp
Fast enemies go at fast speed and have slightly less hp
Immune enemies go at normal speed and have normal hp but take no damage from magic towers (which are ice, fire, and arcane towers)
Boss enemies go at normal speed and have tons of hp and give extra gold and score. Ice towers also have less effect on bosses.
The wave delay decreases after every level until there will be a steady flow of enemies coming at you.
Mine's give you 2% of your gold every 5 minutes, and Churches produce Prayer Points which are used to purchase Wraths of God!