These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Some like that the $20 price includes a level editor that allows the community to create an endless amount of content for their characters. Others are crying out that the developers are letting the community finish the game for them.
Demonic Spiders: One mission in Dragonfall has taser-wielding junkies, which do up to 3 AP damage. This stuns any character they manage to hit, and a junkie can keep that character locked down indefinitely. This wouldn't be so bad normally, but you're in the middle of a Hold the Line mission being flanked from two sides while defending a fragile target from drones that hit twice in a round and trying to keep the junkies from hacking the two consoles which are making the mission bar progress. Seriously, kill these guys on sight.
Complete Monster: Dr. Holmes a.k.a the Emerald City Ripper. He took over the mental hospital and used it's patients for organ trading and grisly Body Horror experiments, which included making designer sex slaves out of them by constructing a body out of various parts, sticking a head with the desired face on it and overriding the brain with chips.
It should be noted that this is relatively tame by Shadowrun standards and could in fact be considered business as usual for many doctors. It also should be pointed out that he is only the first villain you end up putting in the ground. Yes, the Universal Brotherhood is that bad.
Game Breaker: Most moves that manipulate AP effectively give you extra turns. The wall conjurations of the shaman are also very useful, since they can pin down an enemy as you surround them, lock down a hallway or even be used as cover. The AI also likes to cross them, which is also a winning situation for you, especially with the walls that substract AP.
Good Bad Bugs: From the Dragonfall campaign- For whatever reason, Audran is sometimes incapable of opening dialogue with the player during his initial appearance; If this happens, he remains a "neutral" character for the rest of the battle, and follows the player around without attacking them.
Paranoia Fuel: One mission has you storming a corporate building to stop some immoral blood magic research. It is possible for you to steal the research data and sell it for cash. The research in question? A magic that will allow the user to kill a person, no matter where he or she is, so long as the user has access to a blood relative...good luck sleeping if you let that knowledge get out there.
APEX. She can find you anywhere on the net and fry your brain so fast that you can't even jack out. If you don't kill her, you're forever at her mercy, because betraying her ensures that you and anyone you know can never go near the Matrix again.