Seeing people argue over this is making me go nuts!! lol
Here’s the definitive answer … (but I know I will get a lot of reaction on this )
“A simulator attempts to copy various activities from real life in the form of a game for various purposes such as training, analysis, or prediction.”
Happy flying all 
The answer is 42.
It’s neither a simulation nor a game, it’s a way of life.
Yes, but do you know why it’s 42?
Its what you get when you multiply 6 by 9.
It’s a game that simulates flight, that’s all it’s ever been.
its a sim and a game, as all other sim/games are. but its what you make it, for me its a fullblown sim.
MSFS is a game that is better than any other flight sim on the market.
Why is this even a thread? Who cares. Everyone just enjoy the dang sim or move on.
This question was answered million times. MSFS is a game. The genre of the game is simulation. Period.
Its a sim for pc players and a game for xbox users.
Can we say that airline pilots who train on a simulator are on a game ?
Let’s say the simulated environment is not real but can we say that they are on a game ?
Maybe you want to hint at the question of is MSFS a game or a simulation instead ? Just like P3D, X-Plane and others.
It depends on the user. You can fly wherever you want without applying the real rules in use or on the contrary follow the rules applied in the real world.
Just like never having touched a plane in a simulator and left with an A320 or a B737 and let the AP guide you. Or, start with light aircraft, learn the basics of piloting and navigation.
So it’s up to the user to make it a game or a simulator.
MSFS is a promising sim with a lot of sweet features. I like MSFS very much, this is my second sim after DCS in use today. However, CURRENTLY MSFS is not a simulator and not a game. MSFS is developing. As a simulator, IMXO, MSFS is a 50% from 100% of a sim (the situation is improving slowly), as a game… 30% (and no improvement here - I do not see any gaming content here. We can not simulate in MSFS yet like we do in other, with “old history” sims (even FS9 with add-ons looks better) - navigation is not complete (no charts so far, gauges are very basic so far, and so on), ATC is almost no help and confusing forgetting you or not allowing you to answer and so on, aircraft systems are not complete, aerodynamic behavior of many planes is wrong in some aspects (for example, taking off the C-172 we have to use “wrong” pedal), we do not feel forces even on FFB level (and this looks so strange for me that we have to talk about FFB support that I simply have no words to express my amusement that they did not include it - a simulator without FFB is a simulator without a plane for me), we can not even watch AI traffic (“invisible” in airports night time on taxi - we simply are not able to see a taxing aircraft as its lights are not visible at a distance). Visuals in the game are good, however it is not possible to guess distances in the night as night lights near you and at the horizon have the same sises and so on. It is difficult to simulate here. I can not use old navigation to simulate old days of flying as I do not have old planes with 2 RMIs, for example, or use for navigation stars by default. I am not able to use a modern navigation as there are no charts or even approaches and navgauges are far from to be operable, a lot of airports are missing, I am not able to estimate wind speed - no visible smokes or waves or moving trees, I have difficulties to operate at the airport - all those cars on taxiways, suicidal workers, planes invisible in the night… Gaming content? In FSX we had Red Bulls, Nevada racing, nice challenges. In MSFlight 2012… I really miss this game… what a challenges we had there… what a pleasure was searching and learning for those aerocashes… and we we receiving points for this… this was a game… FSW as a game was better developed with all the missions created - we were able to see cracked windows, cargo in the planes and on the ground and so on…
According to “The theory of modelling and simulation” by Ziegler, a simulator is simply something that executes a model. So the model would be a set of equations for example, the computer program implementing those equations would be the simulator. This definition marks MSFS as a simulator, but even first person shooters fit this definition. Does is matter? As a modelling and simulation professional I can honestly say: I don’t care if you call it a game or a simulator. I enjoy MSFS either way.
NO, because a real Simulator that Pilots train on is a million dollar sim, thats something else than a pc sim at 100 dollar, why cant people see this, if you use the pc game as a sim, its a sim, use it as a game its a game with possibility to be a sim, but it will never be up there with the big boys Airliners simulators pilots use.
No Real Wind Affects.
this is a simulator
All computer flight simulators are also video games. 
Microsoft Flight Simulator is great as both.
Long ago, the wisdom of Belushi, Radner, and Chase gave us the notion that there can in fact be a hybrid, so if Shimmer can be both why can’t MSFS?
A “real simulator” need not cost a million dollars. I fly a Cirrus SR22 IRL and did part of my transition training, and even Instrument Proficiency checks, in a simulator that had a representation of an SR22 cockpit (with motion) driven by x-plane software. It was harder to fly than the real plane and an excellent training platform for procedures and emergencies. While MSFS still has a way to go, it’s getting better and I for one don’t find the flight model to be so bad as compared to x-plane and P3D. While none of them provide the sense of really flying, they are good procedures trainers for the real thing.