Originally Posted by pixlepix
Hmm, is this a strategy game? I love BTD4, probably the best app I've ever bought.
There are strategy/puzzle elements to the game. There is a 3-tiered scoring system: 1 carrot is rewarded when you obtain the fixed minimum amount of gems for a level, unlocking the next level. 2 carrots are given for a better score, when you get more gems or pass the level more quickly. Finally, 3 carrots are achieved by scoring even higher, often the best or almost best (can't be too mean) score that is attainable.
There are 3 gem types worth 100, 200 and 400. A timer also tracks how long you take to complete the level, awarding the player varying degrees of time bonus points. So there is strategy involved in figuring out the most efficient way to pass each level in order to get that 3 carrot rank, especially in the later levels.