Our minds are a powerful tool. With a little imagination, the words we read in books come to life in a way that is unique to each reader. And a little imagination can go a long way when we're talking about text-based games in the App Store.

Text-based games like Lifeline and A Dark Room are becoming more popular among gamers. Adding proof to the fact these titles will be the next big trend among mobile games is that users are spending on average 9 hours in the new title Invisible Dragons.

Created by Andrey Nikiforov, Ilia Kazantsev and Dmitry Radkovskiy along with Doubble team members , Sergey Korneev and sound designer Vadim Kolosov, Invisible Dragons is the icy apocalyptic mobile strategy game where players must gather resources to survive. The best part? The game is all about dragons.

"Text-based games are about imagination. It's a story about a land where it's extremely freezing and extremely dark, so you need to get as much fire as you can. You start with a small amount of eggs and fire, and with these, you can create dragons, and the previous dragons create more dragons." Nikiforov told Tech Times "The main point of the game is to create as much fire as you can and try to survive because an ice apocalypse is coming, and you need to make everything to prevent it."

But instead of seeing these mystical creatures and a barren, frozen world, the gamer just sees a black background with text detailing the amount of resources harvested. To play, the gamer taps on each of the resources menus, tapping to create dragons, build egg farms, hire gold miners and make upgrades.

"You always have limited resources and you have to control them well," Kazantsev told Tech Times. "You need to have your own strategy."

"You need to find an effective way to get the resources you need to buy. If you have fire, you can hire some miners or build egg farms, so you need to make a decision," Nikiforov elaborated. There are also other cool features like being able to cast spells and time travel.

The player must contemplate each decision, but since this is an infinite game, wrong choices only help them figure out a better way to advance in the game.

"You can't lose the game, you always find yourself doing better and moving forward," Kazantsev said.

For example, there is chapter about sacrifice where the player must kill the dragon empire. While this sounds like the player did something wrong, in fact the player is reborn with special abilities. Players can finish the chapters and be able to keep on playing, this time with power ups.

And instead of having levels, Invisible Dragons has a more seamless gameplay where there are no clear end points besides some checkpoints. This makes it really hard to stop playing — even though there are no pictures shown in the game.

"Text-based games are about challenging your imagination. Of course, you have no dragons at all — you can't see the eggs, you can't see the gold, but when you are playing, I think they they can imagine this," Nikiforov said.

And, of course, the sounds in the game help make the story come more to life. "The sound design is also very unique for this game," Nikiforov said. "There are about 150 different sounds, with about 7 or 8 sounds for one tap."

So why name it Invisible Dragons?

"First, because you can't see them," Nikiforov said.

The second reason I cannot reveal and will leave it up to gamers to find this "secret meaning of the app" for themselves, although the creators say this will probably take months for gamers to learn.

I've played text-based games before, but was surprised how much I was captivated by a game that just required a few taps to play, especially since as a gamer I am attracted to powerful visuals (although I do have a wild imagination). This got me wondering about the trend of these apps.

"For us, we wanted to introduce this genre of text-based games to a wider audiences because right now they are not very popular," Kazantsev said.

"Text-based games were very popular 20 years ago because it was very difficult to make the graphics and text was something very easy to do and work with," Nikiforov added.

After releasing the AirPano Travel Book app, Nikiforov and Kazantsev wanted to do something new in games and challenge themselves to make something that looks amazing while also being limited. Since there are only 10 games in the App Store that are text-based, this looked like the genre to explore. They also wanted to make an app specifically for Apple Watch.

"For Apple Watch, it's a perfect app because when you see pictures on the watch they look weird because you have a really small device," Nikiforov said. "And when you play with numbers, text and colors, it fits perfect."

They used Apple guidelines to create the game, spending days, for example, to make the "perfect purple from Apple."

"When you first see the app, you might say it's a simple design, but it's really hard work to make a game without pictures, the graphics are not so simple," Nikiforov said, "Why invent something new in UI, if we can follow the [Apple] guidelines very strictly to make something."

This helps the app feel very native, Kazantsev said. "The design is not how it look, it's how it behaves," he added.

Because the game is designed specially for iOS, the Doubble team will have to make a separate version for Android from scratch, something it plans to do in the future. For now, the app is receiving praise from Apple, which listed it as one of the best new strategy games in the App Store in the U.S. According to statistics from the team, the game has an 81 percent retention rate after the first day of downloading, and a 46 percent retention rate after 14 days.

The creators also decided to make this a paid-for title so that ads do not interfere with the gameplay and it has a more high-quality, premium feel.

Invisible Dragons is available to download from iOS for $2.99.