Gemini: Space Tower Defense
Build, Upgrade & Defeat Bosses
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Your last line of defense starts here. Build a sci-fi arsenal, face alien bosses, and try the first two sectors free. More sectors and difficulties sold separately.
Build your last line of defense against an alien invasion. Gemini is a sci-fi tower defense game where placement, weapon combinations, and upgrade choices shape every battle.
PLAN YOUR DEFENSE
Spend battle gold to deploy towers before each wave. Combine laser fire, freezing shots, flames, sniper rounds, and missiles to hold back advancing enemies.
EVOLVE YOUR ARSENAL
Use earned score in Tower Lab to improve your towers. Adjust your upgrades and combine different weapons for the threats ahead. Zoom in on the action and choose when to call air support.
FACE THE INVASION
The full campaign spans nine planetary sectors with distinct terrain, enemy abilities, and powerful bosses.
FREE TRIAL AND OPTIONAL PURCHASES
Play sectors 1–2 on Normal difficulty free. A separate one-time campaign purchase unlocks access to sectors 3–9, with sequential progression still required. Fel difficulty with the Poison tower and Void difficulty with the Thunder tower are separate one-time purchases; neither includes the campaign expansion or the other difficulty. Complete all nine sectors in Void campaign mode to unlock Endless mode. Buying Void alone does not unlock Endless. The Holy tower unlocks through its free tutorial. Restore purchases from Settings.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
GeminiDefense is now Gemini: Space Tower Defense.
• Clearer crowded battles: persistent enemy ability halos and Fel/Void effects surrounding enemies are hidden. Their gameplay effects remain active.
Your existing game progress and purchases are retained when updating this app.
The developer, Blue Rain, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Sun Jian
- Size
- 684.7 MB
- Category
- Strategy
- Compatibility
Requires iOS 15.0 or later and a device with the A12 Bionic chip or later.
- iPhone
Requires iOS 15.0 or later and a device with the A12 Bionic chip or later.
• iPhone XS
• iPhone XS Max
• iPhone XR
• iPhone 11
• iPhone 11 Pro
• iPhone 11 Pro Max
• iPhone SE (2nd generation)
• iPhone 12 mini
• iPhone 12
• iPhone 12 Pro
• iPhone 12 Pro Max
• iPhone 13 Pro
• iPhone 13 Pro Max
• iPhone 13 mini
• iPhone 13
• iPhone SE (3rd generation)
• iPhone 14
• iPhone 14 Plus
• iPhone 14 Pro
• iPhone 14 Pro Max
• iPhone 15
• iPhone 15 Plus
• iPhone 15 Pro
• iPhone 15 Pro Max
• iPhone 16
• iPhone 16 Plus
• iPhone 16 Pro
• iPhone 16 Pro Max
• iPhone 16e
• iPhone 17 Pro
• iPhone 17 Pro Max
• iPhone 17
• iPhone Air
• iPhone 17e
• iPhone 18 Pro
• iPhone 18 Pro Max
• iPhone Duo - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later and a device with the A12 Bionic chip or later.
- iPhone
- Languages
English and 2 more
- English, Simplified Chinese, Traditional Chinese
- Age Rating
16+
- 16+
- Infrequent
Cartoon or Fantasy Violence
- In-App Purchases
Yes
- Void + Thunder Tower $1.99
- Fel + Poison Tower $1.99
- Campaign: Sectors 3-9 $2.99
- Copyright
- © 2026 GDefense