The Lock vs Underdark
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
The Lock
A unique puzzle game where players guess numbers using a spinner. It offers immersive haptic feedback and engaging visuals to guide players. Unlock and collect various themes as you progress through the challenges.
- Number guessing gameplay
- Spinner mechanic
- Haptic feedback
- Visual hints
- Collectible themes
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A puzzle game to guess numbers with a spinner. Enjoy haptic feedback and visuals as hints and collect different themes. The Lock: Game
Underdark
Defend the Eternal Flame from relentless dark forces in this tactical tower defense game. Strategically place towers, choose powerful buffs, and level up unique heroes to create an impenetrable defense. Enjoy one-handed gameplay for fun anytime, anywhere.
- Defend the Eternal Flame
- One-handed gameplay
- Customize defense strategy
- Level up heroes
- Unique hero abilities
- Strategic tower placement
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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!
Screenshots
Verdict
The clearest difference is in-app purchases: The Lock at none against Underdark's 10. The Lock also leads on ads (none vs shown) and review sentiment (100% vs 72%). Underdark's advantage is ratings volume (4.1K vs 6). On price, update cadence and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Underdark sells 10 one-off in-app purchases. The Lock asks for nothing beyond the download.
The Lock holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Underdark has 4.1K ratings behind it against 6, so its average is the more settled of the two. Written reviews point the same way: 100% of The Lock's written reviews are positive against 72% of Underdark's.
The Lock ships an update every 2 days, Underdark every 4 days. The most recent releases landed on November 4, 2026 and November 8, 2026 respectively.
| Parameter | The Lock | Underdark |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (6 ratings) — better | 4.8 (4.1K ratings) |
| Positive reviews | 100.0% of reviews — better | 72.0% of reviews |
| Number of ratings | 6 | 4.1K — better |
| Update frequency | Every 2 days — better | Every 4 days |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 13.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 21 MB | 521 MB |
| Age rating | 4+ | 4+ |
| Developer | Jonathan Taveras | SeungHo Chung |
Customer experience
The Lock
Underdark
Bugs and requests
The Lock
Not enough reviews yet to summarise bugs or requests.
Underdark
Reported bugs
3 issues- Goblin tower factory causing game slowdown
- Consecutive login rewards reset after updates
- Invisible towers in multiplayer
Requested features
5 requests- Ability to rotate towers
- Move towers after placement
- More enemy variety and animations
- Improved co-op mode
- Simplified progression system
In-app purchases
The Lock
No in-app purchases
Underdark
- daily_package_01$0.99
- blade_pakcage$2.99
- daily_package_02$2.99
Show 7 moreShow fewer
- exp_2x$3.49
- Event Package 2$3.99
- add_speed$7.49
- season_superpass_1$7.99
- pack_remove_ads$7.99
- pack_remove_ads2$10.99
- season_hyperpass_1$18.99
