Giant ants shoot orange acid from their butts, but explode into green goop when blasted with a grenade. 30-story-tall robots with plasma cannons for arms explode in fireballs so big, they obscure your entire field of vision. You can bring down an entire skyscraper with a single, well-aimed rocket, and then climb into the helicopter that used to be on its roof to make it easier to pump a mutant alien dinosaur full of missiles without being torched by its flame breath.
If anyone ever tells us again that video games aren't educational, we're going to point to these and other important lessons we've learned from campy, third-person sci-fi blaster Earth Defense Force 2017. Then we're going to say, "So, now who do you want guarding your backside when the alien invasion force shows up and starts laying it down, Ms. Cragazzle? Huh? Yeah, that's what we thought" because we've wanted to say that ever since grade school, but never got the chance before.