Awesome Music: The enemy agent encounter from Syndicate. Awesome enough that Skrillex and Flux Pavilion remixed it for the 2012 reboot, the former is used for the first boss fight in the reboot game.
Syndicate Wars. The increase in details, fully destructible environments and a more comprehensible story with two playable sides are praised. But the numerous "cheap difficulty" segments of the game and terrible 3D graphics, UI (especially the font), and audio are the oft-criticized aspects of the game (especially the Playstation version).
Difficulty Spike: In the last few levels in Syndicate Wars, your enemies start carrying Plasma Lances as their standard gun. These powerful energy weapons fire rapidly, have a good range, and can kill your agents very quickly. While there are plenty of other dangerous weapons such as (rocket) Launchers, High Explosives, Long Range Rifles or Nuclear Grenades, all of these other weapons either have long reload times or give you some time to react (rockets and grenades take time to hit you, explosives must be planted); Plasma Lances give you almost none.
Game-Breaker: The Stasis Field in Syndicate Wars. It's a 'weapon' that puts anyone in the affected field in a period of Bullet Time. This can make the myriad of swarms and Demonic Spiders vulnerable to your weapons; invaluable in the late game missions where enemies wield the Plasma Lance.
Speaking of which, the Plasma Lance is the top general purpose weapon of the game. Fast rate of fire, very accurate, uses almost no energy, good range, and it hits like a truck. Once you get your hands on one there's no point in using Launchers or Pulse Lasers.
If you can spare the credits, the Graviton Gun is stupidly overpowered. Thanks to its energy bleed off, it will wipe out entire maps. While counterproductive for Escort Missions, using it for straight eliminations is ridiculously easy.
Good Bad Bugs: Playing the game on a modern computer will have an unexpected benefit. Time will pass more rapidly, meaning your income will flow amazingly fast and your research will be done in record time. Early missions will then become a joke since your squad will be able to equip the latest weapons and body modifications.
Syndicate Wars has a bug in the PC port, where you sell a weapon from the first three agents, select all the agents, then select the weapon you want to buy or sell. In this case, the sell button is still active. This can be done ad nauseum for easy money, and even before you begin the first mission of the game.
Most Wonderful Sound: The Persuadatron working its magic. The exact same sound has been inherited by the 2012 game.
The minigun's short bursts of death. Again, inherited directly.
The jingle that plays once you've finished a mission.
The Leonardo Device (used by the Syndicate to "enhance" their agents), a giant wheel that holds the subject in a "Vitruvian Man" position (hence the name, presumably) and then rips bits off them to replace with cybernetics.
There's also the agent 'recruitment' process, which involves finding a random innocent civilian with the appropriate physique, kidnapping them, implanting a mind-control chip in their brain to suppress their free will, then strapping them into the aforementioned device to receive modifications.
Surprise Difficulty: The expansion pack, despite using the same map structure in the original game, is much harder than the original. You practically need to memorize the map and in-mission events before you can even attempt to complete a level.
The Atlantic Accelerator in the original game. To elaborate, all the syndicates and the guards have teamed up to take you and your agents down, and they are all durable and armed to the teeth. As soon as you land, your agents will be gunned down the moment you take a single step to the enemies' line of vision. Unless you have agents with lasers, shields, launchers, or a combo of the three, this mission will be impossible to complete.
The space station level at the end of Syndicate Wars, if you're playing as Eurocorp (it's part 2 of 3 of the final mission for Eurocorp, but if you're playing the Church, you go directly from part 1 to part 3). What makes it most obnoxious is that being on a space station, any explosion will take out the entire level and your agents. And almost every single enemy agent in the level carries a bomb which will be armed upon death. Oh, and there are several stasis field traps in the station, which make it difficult for your agents to reach said bombs before they detonate.
The infamous Syndicate Wars mission The Dead Zone (Church mission 18). Your objective is to penetrate a compound and persuade a certain Eurocorp soldier, then take him back to your starting point. There is a whole slew of things that can make you fail, and many of them are very difficult to avoid and can only be detected through trial-and-error:
The entire city is full of booby-traps, which are very difficult to see and will almost certainly kill at least one of your agents if you run into them.
Someone has control of a defence satellite above the city, and will use it to bombard almost every area outside the compound soon after you enter any given area (though they will not target the same area twice).
The city is absolutely crawling with Unguided; while not too tough, chances are that they will distract you or hold you up while your agents fall foul of one of the previously mentioned threats.
You need to persuade 15 civilians before you can persuade your target - due to all the explosions that will occur because of everything mentioned above, there is a very real chance that not enough civilians will be left alive for you to achieve your goal.
When you finally reach the Eurocorp compound, which, by the way, can only be reached by train (IML link), you will find that it is heavily guarded, and a few of the guards are armed with extremely powerful Plasma Lances - if you are not careful, you can easily lose more agents here.
Perhaps the most frustratingly, once you attack the Eurocorp soldiers, you have only a limited amount of time before a lone Eurocorp agent decides to kill your target, presumably to prevent him from falling into your hands.
Finally, you actually have to return your target to your starting point, which is normally easy, but might not be if you weren't thorough in neutralizing all the threats outside the compound.
2012 Series Reboot:
Anvilicious: Richard Morgan stated that the themes in the original were "subtle" and he was "playing them up," which seems to translate to beating you over the head with the idea that the Crapsack World of Syndicate is, in fact, not nice.
Breather Level: The levels "EuroCorp," "The Floating City," "Downzone," and "Human Resources" feature no actual combat, and focus more on world-building and exposition.
Jack Denham, the CEO of EuroCorp, gained immense power with his DART chips—which work like computers inserted into the brain—and will do anything to maintain his dominance. Forcefully drafting agents by finding babies with good combat genes and killing their parents, Jack uses his agents to terminate any opposition to EuroCorp, uncaring if civilians get involved. When a section of Manhattan rioted due to food shortages, Jack responded by sealing off the poverty-stricken area and leaving them to starve.
Agent Jules Merit is Jack's head enforcer and a callous killer. Encouraging his protégé, Miles Kilo, to not worry about killing civilians, Merit goes on to shoot an unarmed man just moments into their first mission. While the duo escape by train, Merit makes a point of shooting each and every passenger he comes across in a car, before tricking the conductor into opening the locomotive room and killing him too. When a EuroCorp scientist turns against the company out of disgust with the company's practices, Merit happily tortures her to mentally break her so her DART chip can be extracted.
Fanon Discontinuity: Fans of the original games were less than pleased with the reboot.
It's Short, So It Sucks!: The game suffers from this big time, being roughly the same length as a pretty average First-Person Shooter. The game includes a seperate, full co-op campaign, but it has minimum story and the combat isn't as fluid as single-player due to being designed for internet play.
Nightmare Fuel: Chip extraction. This is done with a specialized tool which consists of a handle with a spike at the end which you jab into a person's ear or nostril, whereupon thin cables extend from the spike, dig into the brain and tear the chip out. The game gives you a lovely X-ray view of the head so you can better appreciate what is happening. It seems generally expected that the person you use it on should already be dead before extracting their chip.
and Nero [2]