Comparison

Defend the Brain vs Protocol 4

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

Head to head
About

Defend the Brain

Test your brain's speed and dominance between the left and right hemispheres. Compete globally in a game of split-second reactions. See if you can keep up with historical geniuses.

Highlights
  • Brain speed test
  • Left vs. Right brain dominance
  • Global leaderboards
  • Split-second reaction challenges
  • Compete with friends
Read full description

Your brain is much faster than you think. Maybe the world's fastest. Find out now! Compete with friends from around the world. A breathtaking game of 0.000001 seconds. The game ends when you give up. Challenge it now! The right hand is connected to the left brain and the left hand is connected to the right brain. If you use both hands at the same time, which brain will you use more? Who is your brain like? Would you like to use your left brain as much as Da Vinci, Newton and Edison? Or will he use his right brain as much as Archimedes, Mozart, and Beethoven? Test it now! Pixel Bistro is a creative studio. We are trying new innovations in the digital world. Privacy Policy We believe privacy is very important. Please consult our Web site privacy page.

About

Protocol 4

Features
Read full description

Crack the code before your rival does. Protocol 4 is a hacker game of pure deduction. Every guess gives you signal readings; you break the passcode with logic, not luck. Play solo, take on the Daily Operation, or duel another operator in real time. REAL-TIME PvP DUELS Race: one passcode, two operators. First one through wins. Standoff: each of you sets the code the other must break. Two codes, one clock, and you watch them close in on yours. Outsmart your rival and claim the reward. DAILY OPERATION A new code every day, the same for everyone. Crack it, climb the daily leaderboard and earn double XP. BUILD YOUR EMPIRE Assemble mining rigs, expand your vault, and run overclocks. Your network keeps earning credits while you are away. SYNDICATES AND TERRITORY Join one of three syndicates, claim territory on the map, and take your share of the pot that every raid feeds. RAIDS Break into a rival operator's grid and take what they left unguarded, then set your own defenses before they come for you. GLOBAL LEADERBOARD Earn XP and climb fifteen ranks to become the ultimate Server King. MORE WAYS TO PLAY Quick Hacks for fast action, Training to sharpen your deduction, and 18 career contracts plus fresh daily missions. ARSENAL OF TOOLS Oracle Scan, Double XP and more hacking tools to gain the upper hand when a code will not give. Play in English, Turkish, Spanish, French, German or Portuguese, on iPhone and iPad. Are you ready to initiate Protocol 4?

Screenshots

Defend the Brain4 screens
Protocol 44 screens

Verdict

The call

The clearest difference is ads: Defend the Brain at none against Protocol 4's shown. Defend the Brain also leads on update cadence (every 5 weeks vs every 3 months) and iOS requirement (8.0 vs 17.0). On price, 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

Both are free to download. Defend the Brain sells 1 one-off in-app purchase and Protocol 4 sells 7 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Defend the Brain ships an update every 5 weeks, Protocol 4 every 3 months. Both last shipped on October 8, 2026.

Scorecard3 real differences · 6 level
Defend the Brain versus Protocol 4: the parameters behind the verdict, then further details
ParameterDefend the BrainProtocol 4
PriceFreeFree
Rating5.0 (2 ratings) — better—
Number of ratings2 — better—
Update frequencyEvery 5 weeks — betterEvery 3 months
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS8.0 — better17.0
Further details — not scored
Size57 MB12 MB
Age rating9+4+
DeveloperPixel BistroHAKAN OZGER

In-app purchases

1 purchases

Defend the Brain

One-time1
  • Remove Ads$0.99
7 purchases

Protocol 4

One-time7
  • Pocket Change$0.99
  • Starter Kit$1.99
  • Agent License$2.99
Show 4 more
  • Hacker's Stash$4.99
  • Pro Kit$4.99
  • Trust Fund$9.99
  • Master Kit$9.99

Questions

Is Defend the Brain free?
Defend the Brain is free to download, with in-app purchases available.
Is Protocol 4 free?
Protocol 4 is free to download, with in-app purchases available.
Do Defend the Brain or Protocol 4 have ads?
Protocol 4 shows ads; Defend the Brain does not.
Which is updated more often, Defend the Brain or Protocol 4?
Defend the Brain ships an update every 5 weeks, and Protocol 4 every 3 months. Most recently, Defend the Brain was updated on October 8, 2026 and Protocol 4 on October 8, 2026.

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