Complacent Gaming Syndrome: Somewhat. There are different types of games, but you will always find people on team deathmatch, even if the other types aren't really seeing attention. There tends to be enough variation in playstyle to avoid this trope on that front.
Demonic Spiders: Burly/Mighty with a jetpack & Rocket Launcher or with a sniper rifle. Jetpackers fly above you and throw rockets faster than you can walk a circle and sniping ones tends to one shot easily. Even though it's not headshot, it will take much health away.
Game Breaker: 1. Witch Doctor 2. Bear Traps 3. Roller skates 4.???? 5. Profit
Goddamn Bats: The light skater and shotgun and/or submachine gun. In terms of lethality they need to be close, so trying to fire from far away won't deal much damage to you, however they are hard to hit, and once they get close they can kill you quickly if they know what they're doing. All of this is offset by low HP, so if you do hit them with a heavier weapon they may be down for the count.