What just happened? Think you might have some old, unopened video games hidden away in your home? Maybe you should have a check — they could be worth a lot of money. That’s what Scott Amos found when a Nintendo game that had been in his attic for 30 years sold for $9,000.

As reported by CNN, the Nevada resident had been asked to clean out some of his childhood junk from his Mom’s attic. On Mother’s Day, he decided to go through his belongings in his childhood home, which he moved out of 20 years ago, and came across a sealed copy of Nintendo’s Kid Icarus. It was still shrink-wrapped and in the bag from J.C. Penney’s catalog department. There was even a receipt that showed the original purchase date and price: $38.45 after taxes on December 8, 1988.

Nobody in Amos’ family can remember buying the game, though the purchase date suggests it was intended as a Christmas present. “All the family has been trying to come up with a hypothesis,” he said. “[My mom] thinks she put it there and never got it back out, and then it ended up in the attic.”

Not knowing the game’s true value, Amos left it on the kitchen counter in reach of his two small children and the dog. He contacted Wata games to find out what it might be worth. When they told him it could be valued at “a pretty good chunk of change,” he told his wife to move the game somewhere safe. “I didn’t want the kids pulling it down or coloring on it,” he said.

Wata Games CEO Deniz Kahn told Amos that another copy of Kid Icarus in similar condition had sold for $10,000. After Amos sent off his game in a heavily wrapped and insured package, it was given a high evaluation and Kahn put him in touch with Heritage Auctions, who eventually sold it for $9,000.

" 'Kid Icarus' is one of those really iconic titles for the Nintendo Entertainment System," said Valarie McLeckie, video game consignment director at Heritage Auctions. "Finding a sealed copy in the wild is very difficult. It's nigh to impossible because there's less than 10 known sealed that are in the hands of collectors currently, and we don't suspect that there are very many, if any, [more] that are still sealed."

Amos has agreed to split the money from the game’s sale 50-50 with his sister, as the family isn’t sure who it was originally meant for.