Super panzer bros

in an alternate timeline of WW2, the war ended in a tie in may of 1945, however, in June of 1945, something unexpected happens, a portal appears in Germany, German scientists are sent to investigate the portal, turtles and weird mushroom head creatures came from the portal, however, they were attacked, and soon, these creatures would attack Germany, and other countries that were involved in the war were also attacked, the creatures were stopped, but, they wanted to find who was responsible from the other side, US, USSR, Germany, France, and Great Britain sent their militaries to the other world. (I own nothing, all rights go to Nintendo for super Mario characters used in the story.)