Grounded - Whoa! - How to kill a Bombardier Beetle
1. Let him get close to bait out the first acid attack, then run away before he shoots it.
2. As soon as he shoots the acid, run in and hold forward and left, or forward and right, to circle strafe him tightly. Melee and acid attacks will both miss you.
3. When he shoots acid again, back up a tiny bit so you don't circle through the acid pool.