Slime Castle — Idle TD Game

Contains adsIn-app purchases
67.6K reviews
Content rating
USK: Ages 12+
1M+
Downloads
Content rating
USK: Ages 12+
Increased Incentives to Buy, Fantasy Violence
In-Game Purchases (Includes Random Items)
Learn more
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About this game

The bad humans are invading the mysterious forest! The slime kingdoms in the forest are facing a tremendous crisis!

As a slime chosen by the Slime Sage, you can enhance your abilities through battles, collect legendary equipment, utilize powerful skills, defeat waves of terrifying enemies, and safeguard the peace of the forest.

Once you are defeated, come back stronger!

Slime Castle is a role-playing idle tower defense game.

Players could enjoy an excellent role development system, countless powerful weapons, and several impressive battle scenes.

==== Game Features ====
-Auto-battle system with simple idle clicker gameplay. Enjoy a delightful time!
-Many distinctive maps and different enemies with unique skills. Explore more secrets of this world!.
-Flexible and diverse upgrade system. Build your exclusive fortress!
-Collect mighty equipment and level up the adorable slimes. Experience an extraordinary adventure!
-Abundant free rewards to claim. No need to worry about gold anymore!
-Set battle strategy by combining fortress, equipments, and control enemies. Find the optimal methods to defeat your enemies!

Now let‘s start the epic idle adventure and embark on the path to become the greatest Slime Hero!

Experienced a problem? Got a suggestion? You can reach us at slimecastle@redtailworks.com
Become a Slime Hero! Defend forest against human invasion in the idle TD game!
Updated on
Oct 13, 2026
Available on
Android, Windows*
*Powered by Intel® technology
Events & offers

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • This app may share these data types with third parties
    Location, Financial info and 3 others
  • This app may collect these data types
    Location, Financial info and 3 others
  • Data isn’t encrypted
  • Data can’t be deleted

Ratings and reviews

65.1K reviews
Dustin Hardin
October 10, 2025
Update: They recently changed the mini games to be much more difficult so that they could sell their new mini game passes. I recommend not playing 🙏 Not F2P friendly. Decent fun for outrageous prices. Want a better (or new) character? You need to drop more than $30 for each one. There is only one high-ranking slime available for F2P players. The pull rates for upgrades are incredibly low considering the price they want you to pay.
92 people found this review helpful
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Azur Interactive Games Limited
August 19, 2025
Hello! Making in-game purchases only speeds up your progress, it's not the only way to get ahead in the game. There are plenty of other ways to earn in-game resources. So, if you're an active player, you can still compete with others. Good luck!
Justin Sane
March 10, 2025
I really don't mind ads, they are fine as long as they are fair. This game has a multitude of ads with tiny few pixel close buttons that will often lead to open the play store and you won't be able to go back into the game. It'll restart and you'll not only loose the ad as viewed if you've played and won a level it'll loose that progress. Also these ads have 3! Times a close button after each other making it happen more often. Some ads will automatically open the app store. Fix it!
7 people found this review helpful
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Azur Interactive Games Limited
March 12, 2025
Hello! Unfortunately, we cannot directly control in-game advertising, as it depends on the regional ads network, but we can contact the network if the advertising is offensive, inappropriate or disrupts your gaming experience.
Inkblack
April 7, 2025
it's just an ad watching game. watch an ad, collect an item, repeat. the first 4 levels are a game, but then it becomes a grind for loot which you can only get by watching ads. you'll watch an ad to gain a key, then you need to watch an ad to use that key. i haven't done a battle in 3 days. i login, watch 10mins of ads and then wait 8 hours and repeat. and the battles are slow, mindless, 15min snooze fest. and there's not much other content.
9 people found this review helpful
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Azur Interactive Games Limited
April 9, 2025
Hello! Ads help us to keep the game free. Thank you for understanding!

What’s new

1. Global-2 Adventure Card and Slime Skill unlock/advanced mechanism adjustments
2. Removal of the slime mutual exclusion mechanism among Expedition, Pickaxe Transport, and Travel Mode
3. Fixed known issues