To expand on this without make the title massive, were gunpowder weapons instantly a game-changer the way things like machine guns or airplanes were or did the technology take much longer to progress? If yes, do early accounts show the gunpowder equipped armies utterly demolishing the non-gunpowder equipped units in battle like how the early machine guns tore through tribal armies during the colonial period?
The earliest use of gunpowder weaponry would be in China where powder itself was first invented. I am not familiar with Chinese history, so I will leave discussion of gunpowder's military use to an expert in that field. In European warfare, gunpowder was known and utilized from the mid-14th century, although the exact date of its introduction to Europeans is not known. Gunpowder was certainly not an instant game-changer, but its potential utility was recognized enough to receive royal attention and funding from most major powers. By 1415, artillery had become vital to sieges and featured prominently in any major assault on a stronghold. Over the course of the following century, gunpowder started to become an asset in field battles as well as sieges, although handguns would only truly come into their own in the 16th century.