I started a replay through of the game, mostly to refresh my memory after 8 years. Here is a rough guide to adversaries in the gameIn game mechanics terms, runners can pick you out easier by sight, and clickers are more sensitive to the sounds the person makes. Essentially, the fungus ate the eyes and clickers now resort to echolocation to get around. Not sure if we will see bloaters...
Runners: Can see you. But they can be strangled which uses no resources. Only really a problem in packs.
Clickers: Cannot see you and navigate by sound. They cannot be killed without spending resources. I die more to clickers than to any other type of infected.
Bloaters: Slow and not very preceptive. If you have a coupel of fire sources, not a problem. If not then problem as fire damages their armor and without that it's a long game of dodge; headshot; dodge, run, headshot.
Humans: More dangerous than infected by a lot. Especially army types with helmets. After a few scenes with a dozen mixed enemies attacking you (especially when sniping or in tanks), I'm happy to see infected again.