Ratings from IGN etc show that they were provided with a simple verison of the game and/or paid lots by the developer to rate it.
This game is a hot mess of bugs and poor decisions, especially the gamebreaking bug where you will lose progress. The game does not save after each race, only if you upgrade your car between races. It also has a bug which causes the game to freeze when upgrading your car. So, people are regularly completing 2 or 3 races in a cup, having the game freeze and then rebooting just to find they have to do all the same race again. BUT, it does record your earnings, xp and any cars bought during the period, you just lose your race progress. Or, you could complete the whol cup without upgrading at all, move t the next cup and find it freezes for some (any) other reason, and you lsoe the progress in the entire cup you just finished. Barring the major issue of losing prgress regualrly (like 80% of all races) in order to win, just buy the best car available for each race and upgrade it after each race. Dificulty around 3 or 4 is simple. Any higher, the lead car has a rocket of an engine and you wil never catch it, no matter how good you are. As for multiplayer, the game becomes smash up derby, where you ram all the cars off the road to get ahead and stay ahead, you 'might' get penalised up to 2 or 3 seconds, but this is meaningless once you get out in front. However being in a crash, whether your fault or not, will result in the mystifying 'avoidable collision' penalty, Ive sen it given for having other cars bounce into me, or hittitng the wall and spinnning into my path at 100mph where there is nothing you can do. If you want a good multiplayer use GT7. If you want a good career mode, hell, even Gran Tursimo 3 was better than this disaster. Turn 10 are the developers and they havent said much despite the numerous compalints and feedback provided directly to them. Getting a refund from xBox seems to be futile, as they are washing their hands of the whole mess as if they have never heard of Forza before. Just dont buy this, save yourself the pain.