Basic Trope: An enemy blinks with a different color when hit.
Straight: The enemy blinks white when hit.
Exaggerated: When the enemy is hit, the whole screen blinks in white color.
Downplayed: Only the touched body part blinks.
Justified: The player's weapon is designed so it makes the enemies emit a luminescent glow.
The enemy blinks white when it regains health.
The enemy is always blinking white, except when hit.
When enemy doesn't take any damage, it makes a high pitched sound to indicate that its vulnerable point wasn't attacked.
Subverted: In the non-interactive tutorial, it's clearly seen that the enemy blinks in a different color when hit. When the enemy is hit ingame, it does not blink in a different color.
Double Subverted: When the enemy is hit, it does not blink in a different color, but that's because it was being hit in an armored area and therefore not taking any damage.
Parodied: All Mooks and bosses are required to pour a strange paint over themselves, which makes a flash every time they're hit. Only certain ones do not.
Zig Zagged: ???
Averted: The enemies don't flash when hitting them.
Enforced: The game creator is forced to make the enemies flash white when damaged, or else others would find his game too different/boring/tough and boycott it.
Lampshaded: "Why do I always keep flashing with white color when hit?"
Invoked: The Mooks and bosses are sick and tired of getting hit without noticing the damage (and hence dying without noticing), so they develop the ability to flash white in order to notice that they are under attack.
Exploited: The boss or Mooks are fought in a very dark cave, so the hero finds out where they are by using and AOE attack to damage the lot, causing each individual Mook to flash.
Discussed: "Why is it enemies keep flashing when I hit them?"
Reconstructed: In order to be able to legitimately use rapid-hitting moves, heroes using them are required to not be seizure prone. That way, they can stand the rapid flashes when they attack an enemy.
Necessary Weasel: Everyone expects Video Game enemies to flash or show a hurt animation when damaged.
Untwisted: The enemy does not seem to flash when hit, but actually does- it just glows with the colour of UV light and therefore cannot be seen.