Maybe it's because real life is such a tough game to beat, but people seem to love looking back at games they've mastered before. Which is why those in the video game business say the retro game market is on the rise.

Jonathan Young can't seem to get off the phone these days with people wanting to buy and sell old video games. From the 8-bit classics to the 64-bit mainstays, when Young and his friends opened Level 7 Games in Denver back in 2009, retro games weren't exactly bringing in the gold coins. 

"We didn't know that this industry was going to go where it has." said Young, "And now, we just can't keep stuff off the shelf."

Yes, those dusty old cartridges you saved your allowance for are still worth something.

"It really depends on the game," said Young, "There are a lot of games that are common. But yeah, it is fair to say you could have a treasure trove of great stuff in your attic."

Most of the retro games at Level 7 run between $5 to $50, with the occasional rare find bringing in much more.

What Young says may be most important to classic gamers is the idea that nostalgia is a game most people just can't seem to put down.

Level 7 recommends before you sell any game, do your homework online. The store uses a free website where buyers and sellers can search how much games sold for on various digital marketplaces.