Opening the iTunes Store.If iTunes doesn't open, click the iTunes application icon in your Dock or on your Windows desktop.Progress Indicator
Opening the iBooks Store.If iBooks doesn't open, click the iBooks app in your Dock.Progress Indicator

iTunes is the world's easiest way to organize and add to your digital media collection.

We are unable to find iTunes on your computer. To buy and download Royal Defense: Invisible Threat by 8Floor, get iTunes now.

Already have iTunes? Click I Have iTunes to open it now.

I Have iTunes Free Download
iTunes for Mac + PC

Royal Defense: Invisible Threat

By 8Floor

Open iTunes to buy and download apps.


The castle needs a hero – hordes of trolls are surrounding it!

Build towers, save money, learn spells, and keep the enemy away! Follow the exciting story of the dwarven kingdom's eternal struggle against the troll hordes, who want only to crush the dwarves and claim their territory. To defeat these monstrous hordes, you must construct defensive towers and units and learn to wield powerful spells. Tap anywhere you like for a handy pop-up menu listing all the units and structures that can be built in each location. Tap existing structures to see how you can upgrade your forces with powerful improvements! All your towers and units have specific stats: Damage, Fire rate, Damage radius, Damage type, as well as various other features, such as Enemy Slowdown and Damage Over Time. Each level also brings new units and structures to help you fight the troll menace. You’ll never be lacking for new and exciting ways of decimating those nasty trolls!

What's New in Version 1.1.6

- 10 new levels for chapter V

- now you can build and upgrade towers for gems


iPhone Screenshot 1
iPhone Screenshot 2
iPhone Screenshot 3
iPhone Screenshot 4
iPhone Screenshot 5
iPad Screenshot 1
iPad Screenshot 2
iPad Screenshot 3
iPad Screenshot 4
iPad Screenshot 5

Customer Reviews

Good TD Game

I'm a TD game addict and would put this in the top TD games just below some of the best like Bloons TD, Kingdom Rush, and Plants v Zombies. I don't get why everyone gets all upset about IAP particularly when a game like this is easy enough to figure out that don't need IAP to beat it. Everyone said the same about how EA destroyed PvZ with IAP and almost skipped it but after playing it, like this game, was again easy enough to beat w/o IAP. Just put some thought into it, try out different defenses, and will beat the it. I liked that levels were hard enough that had to retry each a few times till got right defense. Tip: spend your gems on upgrades and build mines as fast as feasibly possible.

Lots of Fun

This is a great tower defense style game. There is a bit of strategy involved with a lot of upgrades to choose from. I have a lot of tower defense games because they are my favorite ones to play and this game is in my Top10. It's more than just build a tower and shoot. If you want something that takes a little bit of thinking on top of a basic game you will enjoy this app. Don't listen to all the naysayers this game is a lot of fun.

Decent TD game ruined by greedy IAP

This started out as a promising TD game then the updates came. Yes, they added new levels but they also added IAP. I have nothing against a developer making money on IAP, but to make a game dependent on it just ruins the game. This is, after all, a paid game to begin with.

Stay away from this one, there are plenty of legit TD games with IAP, this isn't one of them.

Royal Defense: Invisible Threat
View In iTunes
This app is designed for both iPhone and iPad
  • $0.99
  • Category: Games
  • Updated:
  • Version: 1.1.6
  • Size: 48.7 MB
  • Languages: English, Russian
  • Seller:
Rated 9+ for the following:
  • Infrequent/Mild Cartoon or Fantasy Violence

Compatibility: Requires iOS 4.3 or later. Compatible with iPhone, iPad, and iPod touch.

Customer Ratings

Current Version:
All Versions:

Top In-App Purchases

  1. 300 gems$4.99
  2. 150 gems$2.99
  3. 50 gems$0.99
  4. Unlock Episode 3$0.99
  5. 500 gems$9.99
  6. 1000 gems$19.99
  7. Unlock episode 4$0.99
  8. Unlock episode 5$0.99
  9. Unlock all levels in episode 1$0.99
  10. Unlock all levels in episode 3$0.99