What Valve excels at are details. One of the reasons I keep playing the games and mods are those details. The details are everywhere; in the story, in the design, in the environments and, as relates to this article, in the enemies.
Just think about the range of enemies in all six games released (HL1, BS, OP, HL2, HL2: Ep1 and HL2: Ep2) and you will see that the player is presented with variety at every stage. Let’s take the example of Headcrabs.
In Half-Life 1, the humble horny headcrab (Sorry I had a bet with somebody about alliterations) appeared for the first time. Even this seemingly insignificant enemy had its own details. Not only did it move slowly but it possessed a determination that would see it follow you to the end of the world. Not only that but if it got close enough it would lunge at your head as if its life depended on it, which it usually did!
Now, think about this for a second. This enemy provides a level designer with lots of possibilities. Putting them scattered around areas to keep you wary, drop them from vertical air ducts when you least expect it (Well, at the beginning of custom map making anyway!), put them on narrow ledge somewhere around Black Mesa and you have another obstacle that makes you poop your pants if done in the right way.
What I am trying to say is that even the simplest of behaviour can give rise to great gameplay with careful consideration.
Now, jump forward to Half-Life 2 and suddenly these happy hairless headcrabs (Ha!, I told you I could do it!) start appearing from the ground or being fired into action via a canister, adding another dimension to their versatility.
But wait, it doesn’t end there, oh no! We now have relatives. The poison headcrab that moves in a similar way to its cousin the honest healthy headcrab (Yes, I know but it’s fun!). This time the poisonous headcrab runs away on getting hit the first time. Not a big difference but enough to add variety and finally we have the fast headcrabs. They again add something different to an already expanding enemy list. Of course I could have talked about the way they sometimes fall from Zombies but that’s another story.
Let’s hope that Episode 3 introduces the Icecrab!
My point? Valve Does Details! Yes, capitals. The difference between ordinary and extraordinary is that little bit extra.
So, if you are still with me at this point, (Phew, thanks btw!) make sure that whatever you do, think about the details. Think about everything, from every angle, and don’t limit yourself to what others have done. Of course be realistic but reach, reach for something new and special.