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.
The ending theme of Trauma Team, Gonna Be Here (the series' only vocal track), brought its composer to tears when he heard it play over the ending.
The Bloody Rose stays true to the series' trend of epic final battle themes. However, this one succeeds over the other three such themes in terms of epicness in spades, even if the battle itself isn't quite as frantic as its predecessors.
Rosalia's GUILT. It's an emotional, sad remix of "Vulnerability" from Second Opinion that plays during the final operation of Trauma Team, when CR-S01 injects the cardioplegic solution into Naomi Kimishima's heart, causing it to stop beating and her maximum vitals to start plummeting. You have literally seconds to excise the Twisted Rosalia virus that has taken over her heart before her vitals peg at zero, and no Healing Touch to see you across the finish line. You screw up, and that's it: Naomi fucking dies.
Under the Knife 2 and New Blood had their soundtracks composed and arranged by Manabu Namiki, a name that will be very familiar to a lot of shmup players.
The first Big Bad, Erick Von Reitenau aka Adam, is the hypocritical Nietzsche Wannabe leader of a terrorist organization who believes medicine is a product of the devil and mankind deserves to be destroyed for rejecting the "gift" of death. In order to do so, he has created artificial parasites called GUILT, all of which are highly contagious and capable of killing their victims in horrible ways all while claiming biblical justification by equating GUILT with the Seven Plagues of Revelation and himself with the "devouring angel" Abbadon (yup, the one with the locusts), all the while boasting to Derek that he alone will watch as Derek and friends burn in Hell. Despicable, yes, but when Derek and Angie join the raid on Delphi's floating headquarters, they discover something that makes him truly irredeemable - in order to cultivate his biological weapon, Adam has kept seven children (dubbed "Sinners" to go with his deranged ideology) in a nightmarish near-death state as culture grounds for the GUILT. Makes it even worse when you think such a horrible fate could have befallen Angie as well...
And, in the sequel, Adam's grandson Heinrich is an even worse person than his already despicable grandfather ever was. He used his own son and daughter as GUILT living incubators.
Ensemble Darkhorse: Victor Niguel and "Little Guy". The latter becomes surprisingly popular within the fandom, despite his very minor role.
Linda Reid (a patient) in Under the Knife. The major reasons are that she's at the center of Derek's character development and she's the first GUILT patient.
Fan-Disliked Explanation: Remember how Derek Stiles got infected with GUILT in Second Opinion? Under the Knife 2 introduces post-GUILT syndrome. If it affects him at all or if he takes a medication mentioned later in the game to cure it is never mentioned, and it is unlikely they will ever revisit Derek given the direction they've been taking the series since Trauma Team.
Germans Love David Hasselhoff: This game series is far more popular in America than Japan, to the degree that from Second Opinion onwards, the games are released in North America before Japan.
New Blood and Trauma Team even take place in the United States.
Heartwarming Moment: After Naomi's surgery, when Alyssa comes running in and Naomi clings on for dear life But pretty much any scene of them together is guaranteed to melt your heart.
Hell Is That Noise: If you screw up dissecting Triti, it lets out a horrible scream- rather disturbing, seeing as it is a mass of triangles. This is the sound of the patent's organs slowly petrifying from the outside in.
The song that kicks in for the REALLY desperate First Response missions, known as Pandemic, not the entire song itself (thought it is tense), but the (synth?) guitar riff that starts at the 1:20 mark. It really complements the fact that you're dealing with countless people on the brink of death from a disease ripped straight out of Hell itself.
Ho Yay: Adel and Derek in Under the Knife 2. Especially evident in one scene about halfway through.
How about Derek and any remotely attractive male character? (this is Atlus after all) Tyler and Victor come to mind.
It's Easy, so It Sucks: Trauma Team is notably less difficult than other games; in particular, the final operation is much easier than in past games, much to the chagrin of the fanbase.
Launcher of a Thousand Ships: CR-S01 has been paired with all of main characters of Trauma Team, characters not even in the game, and his sister and adoptive father.
In the Japanese version, we have Adel calling Tsukimori (Japanese version of Derek's surname) with the tone sounds as foreign as possible. Sadly, it becomes "Daktar Tsukimori" instead.
The song "Gentle Breeze" from Under the Knife 2 is now frequently used alongside pictures of deformed or odd-looking shots of SpongeBob SquarePants characters, beginning with Squidward, and going downhill from there.
Older Than They Think: This wasn't the first major surgery-based game (that would be Life and Death) but since it's been fifteen years since that game was made, it is often credited as the first surgical game. It might as well be, considering the rarity of Life and Death these days.
Player Punch: In Under the Knife, you can't help but hate Adam for what he did to Amy Chase. Also, Richard Anderson's death.
And then, the second game punches you again with Emilio's death.
Stop Helping Me!: Angie. Elena to a greater degree, but mostly just because she's irritatingly cheerful. Invoked intentionally in two New Blood operations.
If you run out of time, no matter where you are in the surgery, a doctor stops you and you fail. Yes, even if you cured the patient, stitched him up, and applied antibiotic-gel, and just need to bandage him up, the doctor will stop you and you quit your job in shame.
In-universe example: Maria Torres can't stand any one assisting her in her job unless it's absolutely necessary. And even then, she treats them as incompetent losers.
RONI helpfully tells Gabriel things he already knows, such as what an x-ray is. This is a Justified Tutorial, but it doesn't make Gabe any more happy being told what to do on everything he's already been doing exceptionally well for a living.
That One Level: New Blood has a couple missions that would certainly qualify for this trope (these don't count as That One Boss because there are multiple operations in these missions).
There are four challenge missions that involve treating a series of patients in a simulation. The final one involves one patient with that is infected with Kyriaki, Cheir, and infant Savato, and the one before that involves a simultaneous Deftera and Soma infection.
In the main storyline of New Blood, there is an arguably even harder mission that involves three patients. The first one is a Brachion infection, which is the Puzzle Boss of New Blood. It's not particularly hard, but it eats up a large amount of time and can get nasty if the heads regenerate. The second operation is a simultaneous Cheir and Soma infection, which is nasty combination, but can be overcome with the right strategy and a little luck. The final operation is the worst thing ever. This patient is infected with both Soma and Onyx. This is downright criminal as treating Onyx invariably means taking your eye of Soma to find the hidden Onyx and you are almost guaranteed that a red tumor will harden while doing so. The kicker for these multiple patient operations is that when you lose, you have to start from the beginning, making it all the more annoying considering the Onyx/Soma combination is intricate enough to be its own mission.
"Lost in Flames". Just... "Lost in Flames".
To give this one some context: you're treating a burns victim. The process to treat a burn is simple on paper: inject clear skin with culture fluid, scalpel the skin loose, forceps three pieces of skin onto a burn, secure with antibiotic gel. This is complicated by a couple of things: firstly, some of the wounds are blackened and cauterized, requiring them to be injected with coolant, cut free, and moved away with forceps before donor skin can be placed. Simple enough. The real killer, however, are blood pools. Blood appears frequently and at random spots over the wounds, and will dislodge any unsecured donor skin over the burn. Did I mention the burns overlap, making it far too easy to put a piece of skin over the wrong one, and a blood pool will almost certainly form by the time more is ready? The standard 5-minute timer might be very generous for most ops at this end of the game, but it's hell even on easy here. If you somehow manage to intuit draining all the blood before doing anything else dramatically slows the rate of new pools forming it gets easier, but it's still hell to get a decent rank on.
Every Triti mission is an example of this.
Subverted with Derek's Healing Touch. You can stop eliminate it with that (except maybe in Under the Knife, since you also have to cut the Triti out before you can extract it) but good luck getting an XS rank on it. It's so bad that there's a tutorial video on it on YouTube and not other GUILT that show up after it..
The ninth operation of the original should be mentioned, especially since it's non-GUILT related. The patient's large intestine is suffering from aneurysms. To complete one, first, you have to magnify it. Then, shrink it with a needle until you can scalpel it. Then, forceps it to a tray. Drain the excess blood. Forceps the vessels together. Stitch. It's not the hard the first time, but once multiple ones start appearing, even the Healing Touch won't help. This extends to any aneurysm mission. The danger from them bursting is so great that after the first game this operation almost always takes place within the brain just so you can start and stop immediately, and so the impact of multiple aneurysms bursting at once is more realistic. Hell, this mission was made easier for Second Opinion - on Normal, one fewer aneurysm develops during the last push.
Pempti is less well-known than Triti, but arguably worse. You start by injecting nanomachines into its core, which causes it to withdraw its tissue and then expose itself in self-defense. Now you just blast it with the laser. Simple, right? Of course not, this is an Atlus game. While you're attacking it, Pempti generates mini-cores that can cause lacerations, send up a wave of fluid that creates small tumors, or just drain the vitals directly. It's relatively simple to fight them off, but once you start taking hits, it's easy to get caught in a downward spiral, especially since taking any time to restore vitals means taking the laser off of Pempti and its mini-cores, which causes you to lose more ground. Is it any surprise an entire chapter was devoted to finding a way to kill this thing?
While Trauma Team is notably easier than the past games, getting an XS rank is now much more difficult. Nowhere does this become more apparent than "Blade of Resolve" and "Love in the Ground", which require the player to get all COOL miniranks and to finish absurdly fast.
A good number of Tomoe's missions are these, particularly any mission involving multiple branched-out paths. The one where you have to search for Dr. Cunningham in a huge pile of rubble is the prime example.
Naomi's missions may not be ranked, but they are hard. It's possible to spend over an hour each playing her missions.
The Scrappy: Angie is pretty much the pariah of Trauma Center because of her self-righteous attitude and constant criticizing of Derek (though he does admittedly deserve it sometimes).
Many fans found it extremely hard to forgive Angie for telling Linda, a depressed, suicidal, teenage patient, that she "deserves to die".
But the worst thing she's ever done by far is blaming Derek for Emilio's death, saying that he became arrogant negligent by relying on his Healing Touch! This consequently causes Derek to go into a depressive spiral and lose his Healing Touch for a whole chapter! This is made even more infuriating when you realize that Derek had three patients to go through before he could even get to Emilio!Shouldn't Angie be fired by now?
The Woobie: All of the Sinners, but Emilio takes the cake. Poor Emilio...
Also, in Trauma Team, Rosalia Rosselini. An innocent girl that only wants to help people ended up killed by her own stepfather because she is the carrier of a doomsday virus.
Amy Chase in Under the Knife.
Stoic Woobie: CR-S01/Erhardt Muller in Trauma Team. He was hated by his parents, his adoptive father went insane and killed his sister and thousands of other people. He was then convicted of killing those people and sentenced to 250 years in jail. Even when he can reduce his sentence by performing surgeries, he has to go back to his cell shortly after the operations and thus can't hang out with the rest of the cast. Despite all of this, he doesn't seem that affected on the outside.