Comparison

HydrogenGame vs ONE

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

Head to head
About

HydrogenGame

Features
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【Created by someone who doesn't understand chemistry】 It's okay if you don't understand chemistry or the periodic table! Maybe you can learn while playing? 【Features】 -The rules are the same as that watermelon game. But it's a different playing experience. Because the stage is circular, the elements move all the time. - 4 difficulty levels and 3 game modes. Even for people who are good at games, it is quite difficult to score 5000 points on the highest difficulty level. -You can naturally learn the names of elements while playing. Hydrogen → Helium →……. 【Overview】 "Hydrogen Game" is a puzzle game where you aim to get a high score by dropping 118 types of elements from the periodic table. Players can drop elements. When attached to the same type of element, it changes to the next type of element. If the elements fly out of the circle and hit the wall, the game is over. Elements can be purchased by consuming energy. Use it when it's dangerous. This is a game that uses elements and the periodic table, but even those who don't understand the periodic table can have an explanation during the game, so they can play while understanding the rules. [4 difficulty levels] There are four levels of difficulty: "Easy," "Normal," "Difficult," and "Very Difficult." The higher the difficulty level, the more types of elements will appear. First of all, let's learn the rules of the game with "easy". [3 game modes] Normal mode: You can play with basic rules. Let's start playing with this mode. When you combine elements of the same type, they change into the next type of element. Period + Tribe Mode: This mode has “tribe” rules added to the normal mode. Once you get used to normal mode, try it out. When elements from the same type or family group are combined, they change into the next type of element. Tribe only mode: A mode with only the rules of the tribe. We recommend playing the other two modes before choosing this mode. When you put elements of the same type together, they change to the next element in the same group. 【The goal】 ・Achieve a score of 5000 points. ・Extinguish the 118th element. The game is cleared when you complete the goal in all modes and on all difficulties.

About

ONE

Features
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ONE-DOT GAMES is a sequel to one-dot enemies (released in 2009, with over 290,000 downloads worldwide), originally conceived by game creator Kenji Eno. A free collection of mini games with simple rules that anyone can pick up and play. Enjoy a slightly strange and unique game experience that begins with a single tiny dot.

Screenshots

HydrogenGame4 screens
ONE4 screens

Verdict

The call

The clearest difference is price: ONE at Free against HydrogenGame's $2.99. HydrogenGame's advantage is update cadence (weekly vs monthly) and iOS requirement (12.0 vs 15.0). On ads, in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

ONE is free to download; HydrogenGame costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

HydrogenGame ships an update weekly, ONE monthly. The most recent releases landed on September 11, 2026 and October 2, 2026 respectively.

Scorecard3 real differences · 3 level
HydrogenGame versus ONE: the parameters behind the verdict, then further details
ParameterHydrogenGameONE
Price$2.99Free — better
Update frequencyWeekly — betterMonthly
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS12.0 — better15.0
Further details — not scored
Size89 MB157 MB
Age rating4+4+
DeveloperAkihiro KakoiFrom Yellow To Orange Co., Ltd.

In-app purchases

None

HydrogenGame

No in-app purchases

None

ONE

No in-app purchases

Questions

Is HydrogenGame free?
HydrogenGame costs $2.99, with no in-app purchases.
Is ONE free?
ONE is free to download, with no in-app purchases.
Do HydrogenGame or ONE have ads?
Neither HydrogenGame nor ONE shows ads.
Which is updated more often, HydrogenGame or ONE?
HydrogenGame ships an update weekly, and ONE monthly. Most recently, HydrogenGame was updated on September 11, 2026 and ONE on October 2, 2026.

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