I rented Krusty's Fun House on a three day rental for the NES. It's kind of like Lemmings, except you play as Krusty the Clown and your goal is to lead a bunch of marching rats to their deaths by manipulating the environment.
I needed to move a block from one location to another on an early level. Couldn't do it. No manual of course for a rental. The internet hadn't been invented yet. None of my friends had played it. I tried on and off for two days. Tried pushing, pulling, pressing every button while pushing and pulling, exploring the environment to see if there was something I was missing. No luck.
Later, just messing around, I accidentally vacuumed the block up into Krusty's body, moved around, and defecated it out at another location. Turns out you had to stand on top of the block, press down to make it disappear into your inventory, move, and then press down again to make it magically reappear at the new location. Had to return the game in an hour.