It's also way too easy to fall into temptation to cheat when it comes to emulators. I should know, because I used to download them all the time. Most known emulators have save states, so you can revisit a particular moment you save at. A handful of emulators, especially ZSNES, have a rewind feature, which allows you to go back in time whenever you lose a life. Just try not using those tools when you play games on them. I dare you.

I have used save states, but never to cheat. Just so that I could stop and pick back up wherever I wanted. I was unaware that there was a rewind feature, but I still don't see myself using it.

Dare taken with success.