There are 22 different kinds of bugs with more than enough diversity to have real tactical implications. Certain bugs have other special abilities as well. Some bugs are limited to walking. Pillbugs are the only other bomb-throwing bug, and they curl up into an invulnerable pill when bombed themselves. Good defenders, too.
Cockroaches also have hard shells, and are invulnerable to poison.
Spiders can attack multiple enemies. And so on. Other bugs can jump. There are also jumping spiders. Many bugs can fly.