Zero Below Zero vs Universe Invader 2
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
Zero Below Zero
A challenging puzzle game with simple mechanics but extreme difficulty. Achieve a perfect score on free levels to unlock the rest at no cost. No hints are provided, requiring strategic thinking to solve each unique circle-based puzzle.
- Extremely challenging gameplay
- Unique circle-based puzzles
- Free levels unlockable
- No hints provided
- Inspired by math puzzles
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Don’t let the cute graphics deceive you - this game is HARD. It’s so difficult, that if you get a perfect score on the free levels, you get the rest of the levels for free. The goal sounds easy - all you have to do is make each circle at least zero. The trouble is there are gazillions of moves you can make, and just one will give you a perfect score. Oh, and there are no hints. There are also no ads, subscriptions, tracking, or anything else you wouldn’t want. If you can’t achieve a perfect score on the free levels, you can always admit defeat and pay to unlock the other levels ;) This game is inspired by the dollar game maths puzzle as seen on Numberphile. Don’t expect that to help you though - Zero Below Zero has been made much more difficult!
Universe Invader 2
Embark on an epic space adventure to defend the galaxy from an alien invasion. This arcade shooter combines classic gameplay with stunning modern graphics, intense battles, and challenging boss fights. Collect power-ups and unlock achievements as you fight to save the universe.
- Stunning galaxy graphics
- Intense alien battles
- Epic boss fights
- Collect power-ups and bonuses
- Unlock achievements and rewards
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Universe Invader 2: Alien War - Get ready for an exciting journey through space! Protect the galaxy from an alien invasion in this fun arcade space shooter game. Step into a thrilling universe full of danger and adventure. Universe Invader 2: Alien War combines the excitement of classic arcade games with modern graphics and features. Each level offers new challenges and surprises to keep you entertained. KEY FEATURES OF THE SPACE SHOOTER GAME: - Amazing Graphics: Explore beautifully designed galaxies that look stunning. - Exciting Battles: Fight fast and intense battles against waves of alien enemies. - Epic Boss Fights: Take on giant alien warships in challenging boss levels. - Power-Ups and Bonuses: Collect special items to improve your ship and win battles. - Achievements and Rewards: Unlock achievements and earn rewards as you progress. The universe’s future depends on you! Every alien you defeat brings you closer to solving the mystery of their attack. Can you uncover their plan and bring peace back to the galaxy? Are you ready to be the hero the galaxy needs? Download Universe Invader 2: Alien War today and join the adventure! Get ready, power up your ship, and start the battle—the galaxy is counting on you!
Screenshots
Verdict
The clearest difference is ads: Zero Below Zero at none against Universe Invader 2's shown. Zero Below Zero also leads on rating (5.0 vs 4.8). Universe Invader 2's advantage is update cadence (every 5 weeks vs every 6 months) and ratings volume (85 vs 6). On price, review sentiment, in-app purchases and monetization model 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. Zero Below Zero sells 1 one-off in-app purchase and Universe Invader 2 sells 43 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
Zero Below Zero holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Universe Invader 2 has 85 ratings behind it against 6, so its average is the more settled of the two. Written reviews point the same way: 100% of Zero Below Zero's written reviews are positive against 94% of Universe Invader 2's.
Zero Below Zero ships an update every 6 months, Universe Invader 2 every 5 weeks. The most recent releases landed on September 30, 2026 and October 10, 2026 respectively.
| Parameter | Zero Below Zero | Universe Invader 2 |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (6 ratings) — better | 4.8 (85 ratings) |
| Positive reviews | 100.0% of reviews — better | 94.1% of reviews |
| Number of ratings | 6 | 85 — better |
| Update frequency | Every 6 months | Every 5 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 14.3 — better | 15.0 |
| Further details — not scored | ||
| Size | 4 MB | 466 MB |
| Age rating | 4+ | 9+ |
| Developer | Omar Fahmy | Gcenter |
Customer experience
Zero Below Zero
Universe Invader 2
In-app purchases
Zero Below Zero
- Unlock all levels$3.99
Universe Invader 2
- Bundle Vip 4$0.99
- Lucky Clover's Offer 1$0.99
- Bundle Vip 2$0.99
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- Bundle Vip 1$0.99
- Starter Pack$0.99
- Ruby 2$1.99
- Premium Starter$1.99
- Instant Rank Up 2$1.99
- Ruby Offer 1$1.99
- Endless Item Pass$2.99
- Fighter Trion Launch Discount$2.99
- Fighter K-oni Launch Discount$2.99
- Ruby Offer 4$3.99
- Ruby Offer 2$4.49
- Unlock Hunt Advanced Pass$4.99
- Gold 3$4.99
- Ruby 3$4.99
- Combo Ruby And Gold$4.99
- Instant Rank Up 3$4.99
- War Machine 5$4.99
- War Machine 2$4.99
- War Machine 3$4.99
- Ruby Offer 3$5.99
- Galactic Ruler 1$9.99
- Combo SS Devices$9.99
- Ruby Offer 5$9.99
- Instant Rank Up 5$9.99
- Abyss Void Launch Discount$9.99
- Galactic Ruler 4$9.99
- Galactic Ruler 5$9.99
- Galactic Ruler 8$9.99
- Ruby Offer 6$11.99
- Instant Rank Up 6$11.99
- Scorpio VI - Unlock$12.99
- Instant Rank Up 7$14.99
- Dream Team$19.99
- Abyss Void - Unlock$19.99
- Instant Rank Up 9$24.99
- Instant Rank Up 10$29.99
- Bundle Vip 9$49.99
- Bundle Vip 13$99.99
- Bundle Vip 14$99.99
- Bundle Vip 20$99.99
Questions
Is Zero Below Zero free?
Is Universe Invader 2 free?
Which has better reviews, Zero Below Zero or Universe Invader 2?
Do Zero Below Zero or Universe Invader 2 have ads?
Which is updated more often, Zero Below Zero or Universe Invader 2?
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