- Demonic Spiders: Snipers can aim their guns and fire as soon as they appear on the screen. Getting unexpectedly hit by those guys can be very common and they deal significant damage.
- Goddamned Bats: One common flying enemy is coded to move vertically to your height at just the right time so you keep stumbling into them as you run foward. At least healing potions are common drops from them.
YMMV / Metalgun Slinger