Forza Motorsport/YMMV

"Dan Greenwalt: One driver, M. Rossi (no relation to the great V. Rossi) is one of our fastest and most aggressive drivers. Late in development, he started learning things that we hadn't taught him. He started check braking (A very advanced racing technique, also sorta dirty). Anyway, this was a bit of a scary moment. He was learning faster than we were teaching."
 * And the Fandom Rejoiced: Forza 4's long awaited Porsche Expansion Pack.
 * Anytime a particularly popular car has been announced in a DLC pack.
 * Complacent Gaming Syndrome: Forza 3 often had multiplayer games composed entirely of Audi A5s and A4s. Other "Leaderboard" cars (cars that have the top times for each track) dominated the multiplayer, but none quite as hard as the Audis. Thankfully, the behavior has died down quite a lot in Forza 4, as there are only a few game-breakingly good cars (and players usually get votekicked out of the lobby once they pull out the car).
 * Game Breaker:
 * In a sense, modification, as in Forza 3 and previous games, the AI never has upgraded cars.
 * Things can get deliciously broken when you take a car that technically qualifies for a given race but which no human judge would allow entry. An example, the French Elite Invitational in Forza 3. Usually this is the stomping ground of Peugeot and Renault hatchbacks, but things get interesting if you're bastard enough to bring a Bugatti.
 * Due to how Forza 3 calculates a car's Performance Index (in other words, how "fast" a car is going around a track), All-wheel-drive drivetrains cause your performance index to actually go down, since it adds about a hundred pounds to the car. However, this allows players to then install huge engines, or cut weight from the rest of the car. What effectively happens is online play gets dominated by AWD Audi A5s, Dodge Vipers with AWD drivetrains, and AWD Volkswagens
 * As of Forza 4, these problems have been fixed; AI can be allowed to upgrade their cars, events now have an upper PI limit, and AWD cars/conversions have more PI rather than less.
 * However, upgraded muscle cars are tremendously fast for their class. As a result, a few muscle cars have been banned from setting leaderboard times while the problem is addressed.
 * In Forza 4, Rivals mode is very easily abused. By continually going only a fraction faster than your previous effort you will collect many more bounties than if you set your fastest time straight away.
 * In Forza 4, preforming rear-wheel-drive swaps on cars (like making a Honda Civic, normally FWD, into a RWD Car) causes a massive performance index number drop in cars without any real drop in performance - allowing you to slap on weight removals, turbochargers, and bigger tires without much of a PI increase from the stock car.
 * Good Bad Bugs: Certain clever maneuvers in 2 might allow you to earn obscene amounts of cash. As a consequence, the inflation levels in the Auction House are astounding.
 * Heartwarming Moments: This commercial, from the Dead Island grade sad piano, to the man's attempt for automotive thrills till he's stopped by police, and the icing, an oddly thoughtful narration by Jeremy Clarkson.
 * Memetic Badass: M. Rossi in 2 and 3, though "Memetic Bastard" might be a better way to put it. Who knew an otherwise imperceptible character could be such a universally-reviled Jerkass?
 * Apparently, according to Dan Greenwalt (The Creative Director of Turn 10), M. Rossi even scared the developers.


 * Ruined FOREVER: Toyota Prius and other electric/hybrid cars being in Forza 4 caused a lot of this on the Forza forums.
 * Tear Jerker: The Endangered Species trailer.
 * That One Level:
 * Silverstone. It seems to be the dev's pet level, because it comes up constantly in the singleplayer events. One of the most boring tracks to look at, boring to drive on, and it's full of 90 degree corners, making it an absolute nightmare to drive on online.
 * Forza 4 has two Track Day events that earn the scorn of most players, thanks to the excellently driven AI cars:
 * The Fujimi Kaido event puts you on the arguably the trickiest circuit in the game in an A-class car making your way round superminis and city cars. The combination of steep narrow roads and sharp, blind turns only make the AI even slower than usual, and if they swerve across the road there is no space for you to avoid them. And on the one stretch of relatively straight road, an AI car has usually come to a complete halt.
 * The Nurburgring event isn't much better. You are in an S-class supercar on the "Green Hell" passing small hatchbacks and a couple of SUVs. The width of the SUVs means they will back up many cars behind them that cannot get past. And yes, they are by far the slowest traffic cars on the circuit.
 * New York City in Forza 3. It's basically 2 straightaways on Time Square, three 90 degree turns, and a roundabound, making it tiring to race on. It's even worse in the "New Circuit" version, which adds a chicane on each straightaway - the chicanes will take out at least one person per lap, the chicanes are so narrow that if one car wrecks, all the cars wreck. And finally, the chicanes are placed at the perfect distance to make passing almost impossible unless your car is far, far faster than the person you're passing.
 * Tier-Induced Scrappy: 3 has lots of the High Tier varients of this trope in the "Leaderboard cars", so called because they always get the best times on the leaderboards. Some examples include the Dodge Viper and most things made by Audi (but especially the A5)
 * Four has its fair share (see Game Breaker above)