Board Thread:Questions and Answers/@comment-99.229.138.191-20130222065937/@comment-3153244-20130403104046

No they are not. For example, in Co-op Mode, Dart Monkeys are the only offensive tower that you will be able to afford on Hard if you don't have any premiums/specialty buildings.

Also (in BTD5 generally), since Dart Monkeys are quite cheap, you can hold off bloons with a few of them while you farm (such as apopalypse mode). And...don't understimate the power of Juggernaut (popping power of 100) and Triple Darts (which shoots 3 rapid darts each having a decent 4 popping power), both good upgrades.

SMFC is also an averagely-good ability.