Good Time Max is not based on a true story. It's a work of fiction crafted to entertain and engage the audience with an imaginative plot and characters.
Well, you'd have to look at the details and the source. If there are no claims of it being true or references to real people and events, it's likely not a true story. However, some elements within it might have roots in reality.
Max Manus is based on actual events. The story strives to remain true to the essence of what happened, although for the sake of entertainment and storytelling, certain details might have been embellished or presented differently.