PS4 games on PS5 console

CronusMax Zen direct connection method for PS4 games

 
The most up to date list with the status for which games can be played and which ones cannot be played is maintained by CronusMax Zen and Titan Two direct connections are here.
 
The Console Tuner Titan Two and the CronusMax Zen direct connection methods require the use of a PS4 Specialty controller for "Authentication", or a special dongal for the CM Zen.  The DualSense controller that comes with the PS5 will NOT work for authenticating 3rd party crossover controllers like the Quadstick.
 
The CronusMax Zen direct connection instructions can be found here:  https://beta.cronusmax.com/ps5
 
The Quadstick is set up just like for the PS4, with both the "Boot in PS4 USB mode" and "Titan Two PS4 flag" enabled in the Misc tab of QMP.  The Quadstick should be running a recent firmware build, like 2328 or later.
 
 
Specialty controllers that can be used for Authentication of Cronus Zen or Titan Two:
 
Astro C40 TR
Mad Catz Street Fighter V Arcade FightStick TE2+
Nacon Compact Wired Controller
Nacon Revolution Pro v1
Nacon Revolution Pro v2
Nacon Revolution Pro v3
Nacon Revolution Unlimited Pro
Razer Raiju Tournament Edition
Razer Raiju Ultimate
Scuf Vantage
Scuf Vantage 2