Comparison

One By One vs Assembly Line 2

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

Head to head
About

One By One

Practice arithmetic, algebra, trigonometry, and calculus with a retro-style math game. Level up by solving problems, unlock new challenges, and compete on leaderboards. Enhance your skills with artifacts and strategic upgrades.

Highlights
  • Randomly generated math problems
  • Leveling system with unlockable content
  • Practice arithmetic, algebra, trigonometry, and calculus
  • Retro ASCII art and music style
  • Leaderboards and achievements
  • Math artifacts and upgrades
  • AI battle mode for targeted practice
Features
Read full description

One By One is a retro math study game built for middle and high school students looking to level up their mental math skills. Featuring randomly generated problems, the app lets you switch from basic arithmetic to advanced calculus. You can also target specific practice areas using the One By One Battles mode or the premium Sandbox mode. Key Features Retro Calculator Aesthetic: Enjoy a nostalgic UI designed with classic Unicode and ASCII art, complete with satisfying mechanical key clicks and atmospheric background music. Four Math Disciplines: Practice everything from basic arithmetic and high school algebra to trigonometric functions (complete with a built-in unit circle) and calculus derivatives. Leveling System: Progress all the way from Level 1 to 99, unlocking brand-new question tiers every ten levels. AI Battles & Training: Test your speed in targeted training modes or race against AI opponents to earn in-game rewards. Artifacts & Upgrades: Solve rare "Golden Problems" to collect 25 unique math artifacts featuring 9 distinct upgrades to shape your strategy. Leaderboards & Achievements: Compete across 5 specialized leaderboards, including a balance-based leaderboard, and uncover hidden achievements. Download One By One and start solving math faster than your teacher! Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Assembly Line 2

Build and manage a factory to craft and sell resources. Optimize your assembly line with various machines and upgrades to maximize profits, even while offline. Discover new resources and make strategic decisions to grow your industrial empire.

Highlights
  • Build and optimize 21 different machines
  • Unlock tons of upgrades
  • Craft around 50 unique resources
  • Offline progress generation
  • Informative machine and resource data
  • Progress backup
Features
Read full description

Welcome to Assembly Line 2, the sequel to the factory-building and managing game. Assembly Line 2 combines elements from idle and tycoon games. Make the most money by using different types of machines to build an assembly line to craft resources and sell them. Unlock upgrades to make it more efficient and expand your factory. The goal is simple, build resources and sell them. Starting with a few machines and very basic resources, and using them with more advanced machines to craft and create more complex resources. Your factory will continue generating money even when you are offline. When you return to the game you will have piles of money waiting for you, but don't spend it all in one place! While Assembly Line 2 is an idle game, because you make the layout of your factory, it is up to you to optimize it to make the most money possible. Don't worry if you get lost with all those machines to build, the game offers an information menu so you can see what each machine does at any time. It also offers information on each resource price, so you can make decisions on what to craft. You can also see stats on the amount you are producing. Features: - 21 different machines to build and optimize the best factory. - Tons of upgrades to increase productivity. - Around 50 different unique resources to craft. - Multi-language support. - Backup your progress. - No internet required.

Screenshots

One By One4 screens
Assembly Line 24 screens

Verdict

The call

The clearest difference is in-app purchases: Assembly Line 2 at none against One By One's 3. Assembly Line 2 also leads on ratings volume (1.5K vs 77). One By One's advantage is review sentiment (91% vs 80%). On price, rating, update cadence and ads 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. One By One sells 3 in-app purchases, starting at $1.99 per month. Assembly Line 2 asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.8 for One By One against 4.8 for Assembly Line 2. That said, the two scores are not equally well evidenced: Assembly Line 2 has 1.5K ratings behind it against 77, so its average is the more settled of the two. Written reviews are what separate them: 91% of One By One's written reviews are positive against 80% of Assembly Line 2's.

UpkeepUpdate frequency

One By One ships an update every 2 weeks, Assembly Line 2 weekly. Both last shipped on October 24, 2026.

Scorecard4 real differences · 6 level
One By One versus Assembly Line 2: the parameters behind the verdict, then further details
ParameterOne By OneAssembly Line 2
PriceFreeFree
Rating4.8 (77 ratings)4.8 (1.5K ratings) — better
Positive reviews90.9% of reviews — better79.6% of reviews
Number of ratings771.5K — better
Update frequencyEvery 2 weeksWeekly — better
AdsYesYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesAd-supported — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.014.0 — better
Further details — not scored
Size64 MB138 MB
Age rating4+4+
DeveloperBrice BrownJoao Reis

Customer experience

One By One

All ratings77 ratings
Positive94.8%
Neutral1.3%
Negative3.9%
Written reviews22 reviews
Positive90.9%
Neutral4.5%
Negative4.5%

Assembly Line 2

All ratings1,479 ratings
Positive94.9%
Neutral3.3%
Negative1.8%
Written reviews225 reviews
Positive79.6%
Neutral12.0%
Negative8.4%

Bugs and requests

One By One

Not enough reviews yet to summarise bugs or requests.

Assembly Line 2

Reported bugs

3 issues
  • Inconsistent offline earnings
  • Crafters and splitters stop working
  • Crashes on launch

Requested features

4 requests
  • Copy/paste assembly lines
  • Rotate/flip multiple machines
  • Pause production
  • Better performance optimization

In-app purchases

3 purchases

One By One

Subscriptions2
  • Monthly Support$1.991 Month
  • Yearly Support$12.991 Year
One-time1
  • Lifetime Supporter pass$19.99
None

Assembly Line 2

No in-app purchases

Questions

Is One By One free?
One By One is free to download, with in-app purchases available.
Is Assembly Line 2 free?
Assembly Line 2 is free to download, with no in-app purchases.
Which has better reviews, One By One or Assembly Line 2?
Assembly Line 2 is rated higher. One By One averages 4.8 out of 5 from 77 ratings, while Assembly Line 2 averages 4.8 from 1.5K ratings.
Do One By One or Assembly Line 2 have ads?
Both One By One and Assembly Line 2 show ads.
Which is updated more often, One By One or Assembly Line 2?
One By One ships an update every 2 weeks, and Assembly Line 2 weekly. Most recently, One By One was updated on October 24, 2026 and Assembly Line 2 on October 24, 2026.

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