Flying or wall-crawling specimen would be hard to implement in the current engine.Tripwire won't do it though it would be cool obviously.
Currently the difficulty of each specimen increases slowly per each wave ( Clot -> Stalker -> Gorefast -> Scrake -> FP ).All these apart from clot, which has grab ability, only differ in life, speed and damage in a nutshell..
If we break it down it goes something like this.
FP is a tougher version of Scrake.Stalker is like weaker clot, cause she ain't invisible, ok?The current "invisibility" is just a gimmick.
In reality it's not tough to see Stalkers, so they just become like a clot with different model/skin.
Gorefast is toughest because he can't be kited.
But all of them just charge towards you and don't have any traits which separate them from one another.
Not really.
I aknowledge Crawler as unique though.
Husk/Siren/Bloat are unique too (even though all of them are similar in their own right)
So I mean, tripwire could really update the current specimen somehow.
Give Stalker some sort of "Silent assassin-like" abilities, like doing more damage from behind, causing bleed damage over time when getting hit until healed by syringe, etc.
Make Bloat explode in a wider area, so that he would actually be scary to let close, rather than being a weaker version of siren/husk.
Just do something to refresh the specimen in a simple manner.
We don't necessarily need overly complicated and hard to implement features, like wall crawling, flying or something similar to L4D's anti-corner stacking in a form of dragging or imobilizing.It would be cool, but the current engine would make it tough to implement.So simple changes would suffice