# Underdark:Defense — Tactical Tower Defense

> Tactical tower defense game defending a flame from dark forces. (iPhone/iPad app by SeungHo Chung.)

- Source: https://appshunter.io/ios/app/underdarkdefense/id6482025287 (this page in markdown: same URL + `.md`)
- Developer: [SeungHo Chung](https://appshunter.io/developer/1626940418)
- Category: Games, Casual, Strategy
- Price: Free with in-app purchases
- Rating: 4.80/5 from 3,996 App Store ratings · 824 written reviews indexed
- Age rating: 4+
- Requires: iOS 13.0 · 488 MB
- Languages: American English, Japanese, Korean, Chinese (Simplified, China), Chinese (Traditional, Taiwan)
- Released: 2024-07-02
- Data updated: 2026-08-29
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/underdarkdefense/id6482025287/reviews.md

## What is Underdark?

Defend the Flame from the dark! Level up, strategically place towers, and choose buffs to grow stronger. Keep the light alive!

Defend the Eternal Flame: Experience the thrill of defending the flame from hordes of dark forces that besiege it! Feel the exhilaration as you clear stages, with each victory more satisfying than the last.

One-Handed Gameplay: Enjoy easy-to-master controls, designed for one-handed play. Perfect for strategic fun anytime, anywhere.

Customize Your Defense Strategy: Select buffs and strategically place towers to forge your path of resistance. As you level up and choose your growth buffs, your defense becomes an impenetrable fortress.

Heroic Stand: Choose your guardians to stand against the night. Each hero brings unique abilities to the battlefield. Earn trophies, level up, and enhance your heroes to ensure the flame flickers on through the darkest nights!

## Key features

- Defend the Eternal Flame
- One-handed gameplay
- Customize defense strategy
- Level up and choose buffs
- Hero abilities and enhancements
- Earn trophies

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Event Package 1 | $0.99 | one-time |
| season_hyperpass_1 | $18.99 | one-time |
| add_speed | $7.49 | one-time |
| season_superpass_1 | $7.99 | one-time |
| Event Package 2 | $3.99 | one-time |
| blade_pakcage | $2.99 | one-time |
| pack_remove_ads | $7.99 | one-time |
| daily_package_01 | $0.99 | one-time |
| daily_package_02 | $2.99 | one-time |
| pack_remove_ads2 | $10.99 | one-time |
| hero_legend_santa | $8.99 | one-time |
| exp_2x | $3.49 | one-time |
| weekly_package_01 | $6.99 | one-time |
| pass_hero_115 | $7.49 | one-time |
| hero_legend_tower | $8.99 | one-time |
| hero_legend_armor | $8.99 | one-time |
| Event Package 3 | $8.99 | one-time |
| hero_legend_joker | $8.99 | one-time |
| Event Package 4 | $12.99 | one-time |
| pass_hero_102 | $7.49 | one-time |


## What do users think of Underdark?

Overall sentiment: positive

**Pros**

- 🚀 Addictive gameplay
- 👍 Generous with rewards
- 🚀 Smooth performance
- 👍 No forced ads
- 👍 Unique tower defense mechanics
- 👍 Customizable towers and heroes
- 👍 Great art style

**Cons**

- 🐛 Multiplayer issues
- 🔋 Battery drain
- 🔒 Paywall for progression
- 🔒 Excessive microtransactions
- 🔒 Confusing UI with too many menus

**Commonly reported bugs**

- Goblin tower factory causing game slowdown
- Consecutive login rewards reset after updates
- Invisible towers in multiplayer

**Most requested features**

- Ability to rotate towers
- Move towers after placement
- More enemy variety and animations
- Improved co-op mode
- Simplified progression system

## Recent user reviews (10 of 824)

All indexed reviews: https://appshunter.io/ios/app/underdarkdefense/id6482025287/reviews.md

### 5/5 — Suprisingly a very addicting and fun game

*2026-08-22*

Couple things to go over.

1. Normally tower defense games are idle and very boring. This is not one of those games, you actually get to do stuff and theres some thinking involved.

2. No forced ads or pay to play. Pay to win not really like you can pay but you really dont need to. Like there is pay to win but not by much as you can totally play without spending a single penny.

3. The gameplay is pretty addictive. You really get into it and trying to win is pretty hard sometimes. I like the crows nest i highly recommend using that when you get it.

4. Its not a perfect game dont get me wrong it has some questionable things and annoying small parts. 

For example, the swapping and discarding gear is kinda unnecessary. It would be better just to swap out the lower tier gear for the higher ones. Another shady ish thing is the mulitplayer as i dont think they are real people and it takes decently long to find a match. I could be wrong or they could be all korean or chinese players but idk its a lil sus.

I think in terms of mobile games this game is definitely top tier i highly recommend

### 5/5 — Mount package

*2026-08-20*

Still cant see in game….. even with update. Pls fix asap.

### 1/5 — Typical gacha game

*2026-08-11, version 3.3.6*

Uninteresting upgrade paths, uninteresting gameplay with little skill involved. Every facet of the game has pay to win or watch an add: make the game move faster, unlock more towers, heroes, and items through loot box gambling, and a pvp element to entice you to spend more than your friends. Don’t waste your time.

### 1/5 — Crashes many times a day

*2026-08-09, version 3.3.6*

Game needs update and fix, been crashing a lot over past week.

Update: 2 months later and still crashing every day!!

Fix the memory issues please.

### 4/5 — 同じタワーでマンネリ化

*2026-08-02*

内容としては面白いです。しかし、毎回アイテムの効果を石を使ってコロコロ総入れ替え出来る訳でもないし、特定のタワーだけを使うようになります。そして、マンネリ化。1dayランキングしかやらなくなります。1dayランキングのシステムのゲームが毎日10種以上やれるならサブスクで500円ぐらいならお金も出すのに。普段の900階以上のダンジョンとは別に、1dayランキングのシステムのダンジョンも沢山作って欲しいです。

### 3/5 — Stage 44

*2026-07-31, version 3.3.4*

Unsure what it is about this stage but no matter what I do it’s impossible to beat. Respectfully, I’m not putting money into the game and personally, it feels as though I have reached a paywall. Otherwise, the game is great.

### 5/5 — Melhor Tower Defese EVER!!!

*2026-07-31*

Um dos se não o melhor jogo no estilo de defesa de torre! Underdark dar a possibilidade de personalização e progressão no jogo que uma forma absurda! Amo o jogo! Comprei a versão premium no Android e compro de novo agora!!!

### 4/5 — Great fun!

*2026-07-31, version 3.3.3*

Love this game. It is great fun. Just wish it could be played offline. Constant internet connection for every little action is frustrating.

### 5/5 — Super TD Game

*2026-07-14*

Habt ihr es bald mit den Updates? Einfach jeden Tag ein Update…. Nicht normal

### 3/5 — Would be perfect if available offline.

*2026-07-13, version 3.3.1*

the game is amazing for passing time but find it annoying that you’re *required* to be online in order to play. I understand it’s required for the monetization elements but I still think it’s strange, as it would be perfect for a long car ride or plane trip, given you could play in that situation.

## Frequently asked questions about Underdark

### What is Underdark: Defense?

Underdark: Defense is a tactical tower defense game where players defend the Eternal Flame from waves of dark forces. It involves strategically placing towers, choosing buffs to enhance defenses, and leveling up heroes with unique abilities.

### What are the key features of Underdark: Defense?

Key features include defending the Eternal Flame, one-handed gameplay for accessibility, customizing defense strategies with buffs and tower placement, leveling up heroes, and earning trophies to enhance your guardians.

### Is Underdark: Defense free to play?

The game is free to download and play, but it offers in-app purchases. This means you can enhance your experience or progress faster by buying items or currency within the app.

### Who is the target audience for this game?

This game is designed for players who enjoy strategic gameplay, particularly tower defense enthusiasts. It's also suitable for those who appreciate hero customization and a game that can be played conveniently with one hand.

### What is the main objective in Underdark: Defense?

The primary objective is to prevent the dark forces from reaching and extinguishing the Eternal Flame. Players achieve this by building and upgrading defensive towers, utilizing hero abilities, and strategically selecting growth buffs.

## Version history (last 5 releases)

### 3.3.9 — 2026-08-15

3.3.9 Update Notes

- PVP Dungeon 2 has been added.
- Fixed an issue where clear rewards were not granted when completing another dungeon after playing a PVP Dungeon.
- Fixed an issue where the hero joystick did not work in PVP Dungeons.
- Improved overall game stability.
- Fixed an issue where the Mount Package was not displayed.
- Fixed an issue where monsters could not be defeated after Stage 900.

### 3.3.7 — 2026-08-13

新規イベントを追加しました。

ステージ900以降でモンスターの体力が減少しない問題を修正しました。

乗り物パッケージが正常に表示されない問題を修正しました。

### 3.3.6 — 2026-08-01

“A Princess and a Knight” Rework

- Whenever the Day changes, you can select a weapon for the knight to equip or replace.
- Weapons appear in four grades, with each grade having an equal chance to appear.
- The weapon selection screen now displays the target hand and its currently equipped weapon.
- Skipping a weapon selection now correctly advances the next selection between the left and right hands.

[Ability Changes]

- Level 3: Whenever the princess or knight defeats an enemy, Final Attack and Critical Damage increase by 5%, stacking up to 2,000%. The current bonus is displayed with a buff icon.
- Level 6: Grade 1 and 2 weapons no longer appear; only Grade 3 and 4 weapons appear. Skipping weapon selection grants 1–2 pickaxes.
- Level 9: The knight can equip an additional weapon in the right hand, allowing three weapons in total.
- Level 12: Each time a weapon is equipped or replaced, the princess and knight gain 20% Attack Speed, stacking up to 500%. The current bonus is displayed with a buff icon.

Fixed related issues and improved weapon selection and attack stability.

### 3.3.4 — 2026-07-31

Version 3.3.5 Update

- The August Season has begun!
- Featured Hero: Squirrel Thunder
- Sub Hero: A Princess and a Knight (Remake)
- Improved Squirrel Thunder’s abilities and exclusive buffs.
- Adjusted the balance of Orc and Boar and Mysterious Armor.
- Normal Stages have been expanded to Stage 970.
- Additional bug fixes and stability improvements have been made.

Thank you for playing UnderDark: Defense!

### 3.3.3 — 2026-07-18

This update improves PvP matchmaking and convenience features while addressing several issues.

• Improved PvP matchmaking to search a wider score range over time.
• The dungeon menu now retains the last selected tab and ranking list position.
• Your selected discard rarity is now remembered separately for items, pets, relics, and housing.
• Fixed issues with Blink, game speed, mount abilities, and dungeon lists.

We will continue improving the game for a more stable experience.

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## More apps by SeungHo Chung

- [다크서바이벌](https://appshunter.io/ios/app/id1626940416)
- [Shadow Survival: Vampire game](https://appshunter.io/ios/app/shadow-survival-vampire-game/id6467580965)
- [UnderGuild: Offense](https://appshunter.io/ios/app/underguild-offense/id6752882356)

All apps by SeungHo Chung: https://appshunter.io/developer/1626940418

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*