As a kid, I loved superheroes. So when Marvel announced about 14 years ago that it was turning old comics into films, I was stoked.

That was, until I saw The Incredible Hulk -- you know, the not-so-incredible one. I left the theater not with nostalgia but with a sense of injustice: How could Marvel mess up a character it had crafted decades ago?

That's the risk of retro products: Fans have high expectations. Fail to meet them, and you'll go from hero to villain in a heartbeat. 

How to Go Retro the Right Way

Retro products have established consumer bases, but that can be a double-edged sword. If you want to delight them, you need to get the details right. Here's how to do it:

1. Push the needle toward "new"

Retro products exist in a gray area: They can't be completely new, but they need to be more than the old thing with a fresh coat of paint.

Take trading cards. In May, collectibles company Topps released a new set of Garbage Pail Kids sticker trading cards, which were originally made in the 1980s. Instead of selling physical cards for this new set, the company released them in digital format using the WAX blockchain. 

Within 28 hours of the cards' being on the market, all 12,000 Garbage Pail Kid card packs--a total of 110,000 cards--sold out. Many have since appeared on secondary sites. 

WAX is now teaming up with the Bad Crypto Podcast to create another set of collectible digital trading cards, this one with a superhero spin. Blockchain Heroes includes 50 technologists and leaders from the blockchain space in an alternative, fictional universe. 

Figures like Captain Currency, Lady Lightning, and Data Avenger still have a seed of familiarity, but Blockchain Heroes takes Topps's experience a step further. Having seen that digital cards resonate with fans, WAX is betting that it can lean further toward "new" in its latest line of cards. 

2. Design for dual contexts

Adults use products in different contexts than kids do. Design your product in a way that harks back to the user's old context while being useful in their new one.

When you were young, your parents probably asked you to avoid biking on roads. As an adult cyclist, however, you probably use your bike mostly for commuting.

Some retro bicycle brands, including a partnership a friend of mine created on Shark Tank with Mark Cuban, have caught onto this strategy. While many e-bikes resemble motorcycles, Tower makes electric bikes that look like old-school beach cruisers. Riding on trails brings back memories, but users also get the comfort and convenience of a modern e-bike. 

Put yourself in your user's shoes: How did they use products similar to yours in the past? What are they looking for from a modern-day version? And how can you blend those together in a way that feels good and works well?

3. Focus on functionality

In every product, form and function matter. But when it comes to retro products, a lot of companies put too much stock in form.

When I was a kid, pressure cookers were all the rage. Somewhere in the '90s, though, they totally disappeared, supplanted by slow cookers.

These days, pressure cookers like the Instant Pot are popular again. The reason, as far as I can tell, is that they combine pressure cooking with slow cooking, sautéing, steaming, and a number of other functions. 

Nobody looks at an Instant Pot and gets lost in their childhood memories. What they care about is that a cooking method from their childhood is now available in a product that can also fix all sorts of other foods. 

Retro products have a huge advantage in a captive fan base. But without balance, they're easy to botch. Mixing new and old is only worth it if you've done your homework, and like homework itself, not everything about childhood is worth repeating.