Tom Hall is already a game design legend, after co-founding id Software and Ion Storm and helping create Wolfenstein 3D and Doom. Now, he's brought his talents to the significantly less gory world of Super Mario Maker with a level called "FIND 15 1UPs EPIC MANSION." In addition to the titular hidden power-ups, the tricky level also has three alternate endings (OK, they're just different paths to the flag, but still, technically accurate).
After more than a few tries, we couldn't quite find all 15 and escape with our lives, as you can see in the video above. If you'd like to try your hand, the Course ID is 68B9-000-0036-A704.