Surgeon Simulator

If you've come this far, you can come a little farther. If you're even contemplating going for this its a safe assumption you're familiar with the games general mechanics so I won't bore you to tears with that. Also assuming you have done many of the level specific trophies for time and blood loss, many levels may already have A++s, however many will not. And most of them are total crap.

THE ALIEN OPERATIONS ARE NOT NECESSARY

Rules of thumb here because in depth step by step guides aren't really that helpful at this point:
1) Aim for above 5000mL of blood, 4900 at the least. This will give you A++ in most of the harder levels
2) aim for sub 4 minute times on levels where blood loss isn't really an issue. If your blood loss is incredibly low, time isn't a huge factor, but keep in mind I have gotten A's with phenomenally little blood loss, simply because i was in the 5+ minute range.
3) If you manage to get an A++ on a surgery, keep going and try the next one of the same organ, getting a handle on the surgery is sometimes better than on the environment, OR go outside and get some fresh air. This game is aggravating as hell.
4) Hallway levels are RNG based, get tools ahead of time and place them on your cart if possible, such as the fold under his chin for the needle in the heart transplant
5) Ambulance levels are gambling with random damage if you don't secure the area, throw all the crap out the back or off the bottom of the screen to minimize Bob taking meat damage from the environment
6) Space levels spawn the tools in the same spot every time. Get familiar with how to grab scalpels and starting equipment consistently, as good knife handling is key for those delicate cuts.

Okay now level specific things
HEART SURGERY: the requirements for the heart surgeries are brutal, extremely fast (like sub 3 minutes) with very little blood loss. The strategy that works here is cutting just the middle two ribs on the right side of Bob with the circular saw, this minimizes blood loss from removing the rip cage, as well as being faster. If you're in the ambulance it should dislodge the lung for you when it jerks around, otherwise remove the top rib as well to get a better hand on it, its quite tricky but the lack of blood loss here is key. Note for the hallway level: since time is a huge thing and its the damn hallway, stash a heart next to Bob's ear as soon as one comes by, nothing kills the mood more than getting a great time and waiting for a heart to come by, and missing the A++. Also just restart if the saw doesn't come by in the first 30 seconds.

KIDNEY SURGERY: dealing with the hit detection of the kidneys in the abdomen will be your greatest enemy here, especially in space. Fortunately all the level specific trophies should have knocked these operations out already. If you still need some, become more acquainted with the exact locations of the points to cut out the intestines for less blood loss, and keep that green needle handy, you shouldn't need to remove the ribs at all if you have nimble scalpel fingers.

BRAIN SURGERY: have mercy. Steam users have the benefit of frame rate and mouse sensitivity here where we do not. The best strategy is to use the hammer, lightly tab around the skull, removing the minimal amount possible and avoiding hitting the brain. Time here shouldn't be an issue as its a quick process, but going for the brain stem with the scalpel will be. Remove extra skull from the front so you have a better shot with the knife. If you're in the hallway, make sure to stash a scalpel and spare brain on the little tray while you wait for the hammer to come by on a trolley, as well as a needle if you get the chance.

TEETH TRANSPLANT: We begin the decent into the inferno friends. Restarting to get better teeth RNG placement here isn't frowned upon, we need every advantage we can get. Your main enemies here are the ambulance and space. When removing the teeth, place the tiny hammer inside his mouth slightly and it should count as hitting the teeth repeatedly for massive damage but also fairly significant blood loss so be ready with that needle. I have no advice for space besides touch his face as little as possible to keep his mouth open, it has a mind of its own. For the ambulance, start the surgery by removing as many large dangerous objects from near the teeth container as possible, losing a run because you can't get a grip on the tweezers or teeth is devastating.

EYEBALL TRANSPLANT: the motion to get familiar with here is hitting the eye with the black box. It's a finicky movement, but once you get it down you should be able to get each out reliably in under 10 seconds each. Aim for the outside corner of the eye with a flick movement, it should feel right eventually. As of writing this I have yet to finish that bloody ambulance trophy because of this. To get the eyes out, the pencil for me seems to teleport into his head far too inconsistently to be usable so i recommend the pen for minimal damage, but sometimes the good ol scalpel is just so reliable, and it removes the need to pick up a new tool, time is of the essence here. When going for the eye stalks be careful and slow, don't stab willy nilly, aim for each tendon. Its frustrating and awful. but the practice pays off.

I will admit i swore like a sailor for hours before I finally got them all done. Best of luck to you all.