Tower placement basics most games never teach you
Almost every tower defence game throws you into the first wave without explaining why placement beats stats. The short version: a tower's value is how long enemies stay in its range, not its damage number.
That's why bends and corners are prime real estate. An enemy walking a U-shaped path can sit in one well-placed tower's range three times as long as a tower on a straight stretch.
I also used to spread my towers evenly, which is a trap. Clustering slowers next to hard-hitters creates a kill zone where enemies crawl while taking heavy fire. Spread-out towers just poke everything a little.
Try replaying an early level with these ideas and watch how much easier it gets. It changed how I approach every TD I install.
