Comparison

Sphere TD vs Echo Planet

Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.

Head to head
About

Sphere TD

This tower defense game lets you build custom towers by combining mods to create unique projectile-spamming strategies. Explore maps, research and craft mods, and defend your flying base across numerous levels. Enjoy offline play and cross-platform compatibility with no pay-to-win mechanics.

Highlights
  • Build and mod every tower
  • Combine mods for over a million tower builds
  • Defend maps with up to 5 custom towers
  • Research and craft mods
  • Base can fly and explore maps
  • Offline play with cloud sync
  • Cross-platform mobile and desktop support
Read full description

Sphere TD is a tower defense game with one difference: there are no preset towers. You build every tower yourself by combining mods to spam more projectiles. UNIQUE FEATURES - Build & mod every tower. There are no preset towers. - Defend each map with 5 towers. Max them out and spam more projectiles. - Split your shots, bounce, multiply, shock, burn. The build is up to you. - Your base can fly, towers and all. Explore the maps and mine ores. - Research and craft mods. Just don't run out of energy. WHAT IS IN THE GAME - 41 towers, each with its own grid layout and function - 33 mods, each with tiers, MK upgrades, a B-Side function, and 3 perks, for over a million tower builds - 50 hand-crafted maps with three objectives each - Endless mode after map 50, plus map-specific challenges - A research tree, mod crafting, and a trader - Spheres that scale into elites, bosses, armored, shielded, cloaked and flying - Offline play, with cloud sync and leaderboards - Cross platform: mobile and desktop NO NONSENSE No pay to win. No time gates. No paywalls. No ad spam. No loot boxes. Funding the Galatium Academy is appreciated, never required. MESSAGE FROM THE DEV Hi, I'm Alex, a solo developer, and Sphere TD is my first game. If you like tower defense and building your own towers, you should feel right at home. Come discuss tower builds with other friendly cadets on Discord. I am committed to 10 years of support. You want it, I'll make it. Ready to join the Galatium Academy?

About

Echo Planet

Transform a planet into a star by forging moons that channel power to its core. Upgrade your celestial bodies, stack multipliers, and witness your energy output grow exponentially, even when you're not actively playing. This idle game offers a satisfying progression from small sparks to galaxy-scale power.

Highlights
  • Forge moons to power a planetary core
  • Upgrade moons and stack multipliers
  • Idle progression, play offline
  • Watch signal surge from sparks to galaxy-scale
  • Transform planet into a star
Features
Read full description

Forge moons that beam power into a sleeping planetary core, awakening it and ultimately igniting it into a star. Upgrade your moons, stack multipliers, and watch your signal surge from tiny sparks to galaxy-scale output, even while you’re offline.

Screenshots

Sphere TD4 screens
Echo Planet4 screens

Verdict

The call

The clearest difference is rating: Echo Planet at 4.9 against Sphere TD's 4.6. On price, review sentiment, ratings volume and update cadence 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Sphere TD sells 10 one-off in-app purchases and Echo Planet sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Echo Planet holds the better App Store score, 4.9 against 4.6. Both are backed by a comparable volume of ratings — 10 and 23 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

Sphere TD ships an update every 2 days, Echo Planet every 3 days. The most recent releases landed on November 9, 2026 and November 5, 2026 respectively.

Scorecard1 real difference · 9 level
Sphere TD versus Echo Planet: the parameters behind the verdict, then further details
ParameterSphere TDEcho Planet
PriceFreeFree
Rating4.6 (10 ratings)4.9 (23 ratings) — better
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings1023 — better
Update frequencyEvery 2 days — betterEvery 3 days
AdsYesYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better16.6
Further details — not scored
Size317 MB96 MB
Age rating12+4+
DeveloperStandardIssueGamesMustafa Mohammed

Customer experience

Sphere TD

All ratings10 ratings
Positive90.0%
Neutral0.0%
Negative10.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Echo Planet

All ratings23 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

10 purchases

Sphere TD

One-time10
  • Au Field Ration$4.99
  • Defender Starter Pack$7.99
  • Au Supply Cache$9.99
Show 7 more
  • Galatium Express Token$9.99
  • Galatium Academy Pack$14.99
  • Shadow Broker Vantage$19.99
  • Au Enterprise Fund$24.99
  • Flux Enrichment Grant$24.99
  • Au Strategic Stockpile$49.99
  • Au Global Reserve$99.99
2 purchases

Echo Planet

One-time2
  • Gold Supporter Pack$2.99
  • Diamond Supporter Pack$5.99

Questions

Is Sphere TD free?
Sphere TD is free to download, with in-app purchases available.
Is Echo Planet free?
Echo Planet is free to download, with in-app purchases available.
Which has better reviews, Sphere TD or Echo Planet?
Echo Planet is rated higher. Sphere TD averages 4.6 out of 5 from 10 ratings, while Echo Planet averages 4.9 from 23 ratings.
Do Sphere TD or Echo Planet have ads?
Both Sphere TD and Echo Planet show ads.
Which is updated more often, Sphere TD or Echo Planet?
Sphere TD ships an update every 2 days, and Echo Planet every 3 days. Most recently, Sphere TD was updated on November 9, 2026 and Echo Planet on November 5, 2026.

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