in all reality, germany could have easily prolonged or maybe (the chances were slim indeed) won the war had they waited a year or two more to strengthen their military. Had they had more resources stored to build more panther tanks and more time to perfect the tiger and king tiger along with the jagdpanther, they could have become very unstoppable on the ground. Furthermore, with their development of the jet engine, they could have ruled the skies. Lastly, they also had their own development of atomic weapons underway towards the end of the war.
Thankfully (to some extent), history played out the way it did. It is unfortunate that an estimated 50-60 million people had to die during the war. Approximately 6 million of that was jews alone, with around another 3-4 million in poles, slavs, and other minorities from the holocaust. Pretty hard to comprehend very well.