Let's be completely frank here, the Shenmue games are not good games... I would position them right at average, at best,
BUT it is very easy to see why people love them, they have a lot that is lovable about them.
but also there is a lot of filler and for the most part the game mechanics are extremely limited/dull aside from the fighting.
for me, a flawed game that at least tried to be something special is immensely more interesting than yet another 3rd person game with shooter, stealth and crafting elements
*cough* The Last of Us
*cough* Tomb Raider Reboot
*cough* every fucking Ubisoft game
*cough*
OH IT IS SO FUN SITTING IN A BUSH AND STEALTH KILLING AN ENEMY WITH A BOW AND ARROW... FOR THE 300th TIME... WITHING THE LAST HOUR...
True Crime also had similar combat mechanics, while the rest of the game being way more influenced by Grand Theft Auto series, of course.
I can see those Yakuza-Shenmue similarities. But Yakuza handled the fighting-exploration flow infinite times better, Shenmue was just a free roaming Virtua Fighter and that shows.
Its like Panzer Dragoon Saga, you can give Panzer Dragoon Zwei RPG elements and you can make it more open, but in the end it will be Panzer Dragoon Zwei.
True Crime's fighting mechanics are absolutely god awful tho... they became half way decent in Sleeping Dogs (which was originally True Crime 3)