Hi, The Me-262, Me-163 and He-162 were used in combat definitely, I think some of Ar-234 were used as a recon plane and maybe as a quick bomber during German bombing of bridges over the Rhine at the end of WWII, the Do-335 prototype was tested but never used in combat, P-80 was used by Americans in Italy at the very end of the war but it never gone to dogfight against any Axis plane(they just never met any German or Italian plane becuase of Allied total superiority in the air), Bi-1 and La-7R were tested but never used in combat.
The other jet or rocket planes simulated in the game existed only as projects and never got in the air (Lerche, Go-229 etc.) or got in service after the WWII (MiG-9,..,)
However, i can strongly recommand this game. Buy it and fly it!