Gran Turismo 2 is a broken mess in the best way possible. It improves on its predecessor in almost every way: more cars, more events, much more in-depth tuning, better physics, and more stylistic menus and music. However, it was infamously rushed to release with bugs, oversights and cut features. Thankfully, none of these detract from the game experience, and some actually enhance the game in a backwards way.
When starting in GT Mode, you're given 10,000 credits with absolutely no indication of where to go and what to do next. No hand-holding whatsoever, you're bestowed absolute freedom. You'll probably want to do some of the licence tests straight away, as these will let you enter events with bigger prize amounts to speed up the early game. The Supra, RX-7 Infini III and Silvia K's 1800c are great choices for your first car.
No other GT game embodies 'freedom' more than this one: once you win a few races to buy your first proper car, you'll realize that you don't need an 80's car to enter the 80's event, or a wagon to enter the wagon event. Besides the drivetrain and aspiration events, it's a complete free-for-all, as long as your car meets the power limit. If you want to enter a Suzuki Cappuccino into the muscle car event, nothing's stopping you.
One of the main broken things in this game is the complete lack of tyre wear. Even in endurance races, the tyres your car has equipped won't make a difference, they will always wear at the same rate. This makes super soft racing tyres the most important upgrade in the game, as they have no downside and offer ridiculous amounts of grip.
Something that makes GT2 stand out from the rest of the series is its huge offering of racing modifications. Most cars can receive them, and not only do they kit the car in racing liveries and body kits, they add the ability to adjust downforce. Max downforce, super soft racing tyres and soft front springs can turn any car into a track weapon. You can view all of the game's racing modifications
here.The primary thing that makes the game broken, yet fun, is the prize cars and how little effort it takes to win them. As soon as you get the I-C licence, the game starts throwing race cars at you that can be sold for 125,000 credits or more, even after simple 2-lap races. Race 5 in the 80's cup can be won with your starter car and awards the R30 Silhouette race car, one of the best 591hp cars in the game. Then, you can win race 3 of Gran Turismo All Stars to win the Speed 12, which can be sold for 500,000 credits. Repeat this race, and you'll never have money issues again.
Then, of course, there's the Escudo. One of Gran Turismo's most infamous oversights, a 981hp powerhouse intended for rally driving but still handles very well on tarmac. GT2 doesn't properly model front-wheel drive understeer, so it turns much better than it's supposed to. Using it is basically a free win in any event with an open power limit. Even without it though, this game is still quite easy. As long as your car is somewhat close to the power limit, you'll comfortably win races, especially with tyre upgrades.
We will never get a game like GT2 again. After this, Polyphony would embark on a path of constant course correction while gradually forgetting how to design fun games. GT3 did fix many of GT2's issues (more difficult GT mode, proper tyre wear etc.) but ended up adding a bunch of extra broken stuff in the process. GT4 then tried to fix GT3's issues, but many of the solutions were simply unfun and led to serious issues like save file corruption. It would seem to me that their pride means more to them than the user's experience.
So, while Polyphony fumbles with 7 and whatever it's trying to be, we can be glad that 2 exists and is still being actively supported by the modding scene. We've got
HD 60fps cheat codes,
GT2 Plus and many more ongoing projects worth checking out.