9. Level Select
Yes, I know games autosave themselves practically every five seconds nowadays and already contain chapter select functions but back then, if you ran out of lives or had to cut the power for whatever reason, your hard-earned progress was shot and lost unless that game had a level select function accessed through cheating. Typically, level select wasnt necessarily intended for cheating but during development, developers themselves needed a way to quickly flip through levels while testing, so the asset became mutual and left in the finished product. Level select could have its uses today; maybe you want to show a friend something at his house but have no way of transferring data? Maybe youre inexplicably impatient and want to play the ending first? There are all sorts of reasons to add in this harmless little cheat.